What are the chances that Apple releases a Mac with Alder Lake CPUs? I'm planning on building a new desktop. Rocket Lake is right around the corner, but I don't want to build a rig with the LGA 1200 socket as it will be end of the line and Alder Lake's LGA 1700 socket will allow for upgrades. I'm debating on whether I should build with Rocket Lake or wait for Alder Lake...
I cannot predict the future, but given the stellar performance per watt and overall performance of M1, I think chances are pretty slim that Apple releases an Intel-based Mac again, whether Alder-Lake or some future Intel architecture. But, if Intel gets its mojo back on 10 nm and 7 nm, you never know.
Anyhow, since Alder Lake will still be an x86 CPU, I would presume it would run MacOS, possibly with the need for some kernel patches. If you're debating between Rocket Lake and Alder Lake, if it's for a system you plan to have for a few years, I'd say wait, if at all possible, for Alder Lake. Given as you pointed out that the new LGA1700 will come with new features such as PCIe5 and DDR5, and of course a hybrid core design with big+little cores, increased IPC, and (most likely) better performance-per-watt, given it will be based on the new 10 nm process.
But Rocket Lake seems to be a beast. Leaks are indicating that a 11700K may score 1810 in Geekbench 5 single core. If true, Rocket Lake will be the fastest CPU on the market, from a single core perspective. I imagine Alder Lake will be even better still.