After the controversy over the removal of font smoothing in macOS Mojave (disabling sub pixel anti aliasing?) we've all discussed the likely reason why in this thread.
I've speculated that this spells the end of native non retina displays in the Mac range (ie the venerable MBA and final entry level non retina iMac 21.5").
What about the impact on the mysterious 2018 Mini? If the average Mojave desktop looks worse if you don't have a 4k or 5k display you'd have to assume that the 2018 Mini will allow such displays to be connected - not exactly a massive leap of logic there as any current Intel iGPU can theoretically run a 4k display although the performance might not reach Apple's minimum standards (which are admittedly quite low).
Perhaps not using sub pixel anti aliasing will reduce the toll on the iGPU to improve battery life on laptops (yeah, thinner laptops here we come), improve UI performance, and reduce heat generally in Macs when most users will be on retina screens now? The few people who are using non retina screens can either upgrade to a 4k screen or should be encouraged to upgrade the machine while remaining able to continue using their current machine.
The point is that the Iris Graphics 5100 GPU in the existing 2014 Mini isn't capable of driving a 4k display, so clearly that means the next Mac Mini is almost certainly coming...
OK, perhaps it's coming with a less powerful GPU in mind (ie UHD 620) to keep entry level costs down which would allow Apple to offer better graphics by adding a dGPU to the motherboard as an BTO extra or as standard on a higher SKU.
Addendum:
The theory floated in the paragraph above and earlier in this thread was based on the understanding that Apple's engineering budget for updating the Mini required a single motherboard with a drop in slot for the CPUs which would be used across 3 notional SKUs. This initially disbarred the idea of splitting the Mini range between a 15w CPU and 28w CPU.
I just went over to check the specs on the
i5-8265U (Whiskey Lake) CPU that supersedes the
i5-8250U (Kaby Lake Refresh).
The Whiskey Lake part now appears to use a FCBGA1528 socket - as opposed to the Kaby Lake Refresh part which uses the FC-BGA1356 socket.
This appears to indicate that the i5-8265U now uses the same socket as the i5-8259U and
i5-8269U (Coffee Lake) which are in use in the Touchbar 13" MacBook Pro.
Apple could now produce a rather unimaginative update to the Mini which includes a 15w i5-8265U at the low level, and 2 lots of 28w Iris Graphics powered SKUs in the same enclosure, replacing the Thunderbolt 2 ports with Thunderbolt 3. The i5-8265U also has 16 PCIe lanes, the same as the 28w i5-8259U CPU.
At this stage, we'd probably not be too disappointed by the following SKUs:
RAM: 8Gb across the board, up to 32Gb with DDR4 (probably soldered).
Base SKU: 1.6GHz (4 cores, 8 threads), 1Tb Hard Drive
Mid SKU: 2.3GHz (4 cores, 8 threads), 1Tb Fusion Drive
Top SKU: 2.6GHz (4 cores, 8 threads), 2Tb Fusion Drive
All units to get a price uplift which covers the cost of RAM and better drives. Of course, this leaves the Mini very susceptible to a press release update as it could very much look the same as the existing model, the price has gone up to accommodate a T2 CPU and unexciting storage options.
We could also now see a cheaper to produce non touch bar MacBook Pro variant using the same motherboard as the Touch Bar MacBook Pro but with the 15w i5-8265U CPU (which reportedly has a decent GPU) under less pressure due to Mojave's changes.