Prepare to be disappointed. That didn't even happen in the PPC -> x86 transition. And Intel had a full set of CPU products available before Apple even started the transition. Apple does not. They have had nothing that fully completes in the desktop space. That is why the Mac Mini backslid on ports and number of displays supported. Apple is pretty unlikely going to "fix that" in less than 8 months.
For the x86 transition Apple slid the WWDC to August to have their claim victory party. So June? There is not even a "broken analog clock is right twice a day" precedence for that.
Additionally look at the developer transition kit in the two transtions. For Intel could support driver development for PCi-e cards. Apple Silicon transtion. eGPU are absent. macOS 11 can't do anything except Apple GPU because drivers for nothing else. (or other accerlators/processors that normal sit on PCI-e). So that is delayed also.
The rumors of a "half" sized Mac Pro ... which is probably a move to prune features off the Mac Pro to backslid back to what their later SoC is another indication that they don't have a broad SoC line up on the near term horizon.
The only way Apple completely polishes off the transition to Apple Silicon by the end of 2021 is by dragging the whole back to laptop constraints. There is pretty good chance Apple will finish the laptops in 2021. Given that is 70+ % of the Mac business they would have gotten to the high volume status. Doing the last 10% will be much harder for them given their desired to stay tightly coupled to the iPhone and iPad Pro. ( The M1 die is pretty likely going to show up later as a A14X with some features turned on/off. It is approximately the same size as previous A12X and A10X. )
There could have been an Intel product that was scheduled for end of 2020 that slid into Jan-March 2021. Pandemic slid many products. There have been impacts.
By April-June 2021, I wouldn't expect anything new. There is a substantive problem with macOS 11 being so behind of PCI-e card driver support though. And the huge disruption that Apple has done to device drivers in general ( going from kernel extension IO-Kit to IO-MMU leveraged evictions from the kernel System Kit. ). That probably won't completely settle done to broad completion until macoS 12. So there is a major software component here also that isn't likely to close before another OS iteration. ( similar to the hype where Apple said they were going to "wipe out" HFS+ in a year and ....... did not. Once got into the pragmatic weeds of Fusion drives , HDD support , etc. of which large number of people had it was much more complicated than rolling out to single drive SSD homogenous environment of iOS devices. )
Probably, not going to happen in desktop space; nor with a healthy fraction of the MBP 16" space.
The other problem for Apple TSMC doesn't have that kind of 5nm capacity to soak up 6-7% of Intel output without robbing other customers of capacity. Can grumble about Intel's fab problems but they do have large capacity. It is going to be difficult for Apple to show up and order up 2-3 M more dies of 2-3x the size of the M1 and actually get those wafer starts. (and zero impact on the iPhone SoCs. ).
Apple has lots of money to pragmatically buy up exclusive 5nm lock outs for a short period of time but isn't going to last for a very long time. TSMC will bring up more capacity over 2021, but the problem is that there are dozens of folks with deep pockets that want to feed at the 5nm trough.
It may come to a surprise to everyone who disagrees with me that Apple has been working on Apple Silicon as
early as 2017 and as
late as 2018.
So all the designs and testing of Mac chips to be released by March 2021 and June 2021 are awaiting their scheduled fab manufacturing time.
Apple is an
~$2 trillion company that outputs
5nm process chips. Intel is a
~$0.2 trillion company that is only capable to output
14nm and
10nm chips.
Apple outputs more
iPhones and
iPads combined than the
whole PC industry within 2019.
Intel has ~80% market share while AMD has ~20% market share in the PC CPU market.
Your putting limits on a Apple is laughable.
What I am actually disappointed is with people's lack of understanding how product development cycle, business and supply chain works.
PowerPC to Intel took
less than 7 months. Nov 2021 Mac event to WWDC 2021 tracks as within 7 months.
I never talked about ""half" sized Mac Pro". Neither am I in the position to comment of such a product. If you asked me that concept was made up by someone who could not even afford half the price of a Mac Pro or some writer needing clicks for his article to keep their jobs.
Have you considered the eGPU support will be available at a later date as a macOS update?
What if Apple prioritized eGPU support this month? How many thousands of people out of nearly 15 million M1 Macs would spend more than $1,000 for an eGPU and to be used on a ~$1,000 Mac? Also if the M1's iGPU is equal to a GeForce 1050 Ti how much more expensive of a discreet GPU do you need to make it perform better?
Are over 80% of M1 Mac owners buying an eGPU setup that's 2x the cost of their Mac? Wrong market. Doesn't make sense. M1 Macs are the most affordable Macs and over 80% of their customers wont spend on an eGPU. Thus wasted man power on a feature that less than 20% of M1 Mac users would use.
macOS
detects the eGPU in System Report. So it means that drivers are just missing for the GPU. Up to AMD or Nvidia to do that.
eGPU support should come later for users who would actually use the feature. It's all about timing of release to benefit the most number of users.
Why would anyone who does not need x86 native hardware or certain form factor buy any Intel Macs today? I'm sure there is some demand from today to June 2021 but after WWDC 2021 would demand be ~1%?
Apple makes a better margin continuing to sell Intel Macs released as early as 2017 unchanged as those buying them are not looking for more performance but native Intel hardware. If they want performance then get a M1 or better yet wait for the early 2021 Mac event and mid 2021 Mac event.
TSMC has the capacity to output Mac chips as Apple is smart enough to schedule fab time when iPhone demand softening to allows it. Not to mention
Apple booked all of TSMC's 5nm capacity. ~80% of all Macs that will ship in the next 12 months are using M1. So that's about 14.15 million Macs from November 2020-2021. So that's like ~1.8 million/month M1 chips on average without considering seasonal buying behavior.
Intel has large capacity at 10nm or 14nm but not at
7nm which they're rumored to outsource to TSMC.
No one has as deep pocket as Apple. They can buy out capacity months in advance.
Ever wonder why there's a shortage of PS5s that are on a AMD 7nm process?
I invite everyone before replying to google sources to support their positions. Apple planned this all years in advacne. You don't become a more than $2 trillion company by playing this by ear.