Popularity? More like hoopla. The Mac user base isn’t growing, especially amongst those who want to game. If you wish to stay with the Mac eco-system you have no other choice than to buy an ARM Mac these days. Just as when PowerPC was replaced by INTEL.
Omegal made mention of the ARM client in past posts. I didn’t find the post I wanted to refer to, but here is one that mentions a similar line. Blizzard has never officially said anything about ARM support. So if you are looking for the from the horses mouth sort of links, you’re not going to find one until it is an absolute. Reality is, Blizzard won’t support both clients for long, typically they drop the older client whenever the new expansion roles out. But abandoning INTEL doesn’t mean ongoing ARM support either.