Right on, my friend.
I still haven't decided if I'd get a 16 GB M2 Mac mini or a 24 GB M2 Mac mini (this year or next year, whenever it comes out), but now I'm leaning toward the latter unless some M2 Pro model comes out that is enticing. I definitely do not need a 32 GB Mac Studio.
Part of the reason is the cost. For the M1 Pro MacBook Pro, it costs CA$450 (US$356) to upgrade memory above 16 GB, to 32 GB, at the Apple Canada Education Store. For the M2 MacBook Air, it costs only CA$225 (US178) to upgrade memory above 16 GB, to 24 GB. I presume M2 Mac mini upgrades will be similar.
I know I don't need 32 GB, so paying big bux extra for that just makes no sense. However, it's a lot easier to stomach paying an extra CA$225 to get me to 24 GB, for a machine I plan on keeping more than 5 years.
I was very sure about the importance of 4K HEVC, but admittedly I'm not as well versed as to the direction of AV1 and its politics. However, remember, Apple already licences HEVC anyway for all its iPhones, iPads, Macs, and Apple TVs, and will have to continue doing so for many years too. Also, competitors like Qualcomm won't even include AV1 hardware support in their chipsets until 2023, so adoption in hardware continues to be low, even on the Android side, which is Google's bread-and-butter obviously. Android devices outsell Macs by an order of magnitude.
YouTube will provide support for a long, long time, for existing formats for 4K that Apple already supports. I don't know about 8K, but personally I don't care. 8K is not on the radar for me as something that actually will matter in the greater scheme of things for the next several years.
However, hardware support for AV1 4K in Macs now is also less critical than hardware support was for HEVC 4K in Macs 5 years ago. Back in 2017, even a top-of-the-line iMac Core i7-6700K could not cleanly play back many 4K HEVC 10-bit p60 videos, even with the CPU maxed out and the fans running in vacuum cleaner mode. In 2020, a fanless M1 MacBook Air could already cleanly play back 4K AV1 in software. This is with moderate CPU usage, and AFAIK the MacBook Air could even lightly multitask while doing that. M2 would perform even better.
BTW, in the off chance there is hidden AV1 hardware support that hasn't yet been exposed by macOS and Quicktime, I'd say the chances are it is much more likely to be present in M2 than M1, since Apple significantly updated the hardware codec support in M2.
In summary, I want an M2 Mac mini within the year and while there is no official AV1 support (yet) with M2, I don't expect it to be a real concern for many years on the Mac. And even if one day AV1 becomes a real requirement, M2 already fast enough to provide AV1 decode in software, with only moderate CPU usage for 4K content. And as for 8K, I just don't care much.
Anyhow, maybe it's a good idea you start a new thread on this in the Apple Silicon forum. It's an interesting topic.