Yep, when a computer manufacturer with 10% desktop market share switches processor architectures, surely that will dictate whether the architecture will die. <-- This is sarcasm, to be clear.
Strangely enough, Apple's architectural hardware choices have a history of having effects on the broader market disproportionately to their market share.
aarch64 is not only chosen by apple. There are so many linux arm64 sbc floating around. MS also has their own plan on arm platform