Jon,
Yes rumours suggest first MAC with ARM will be in the MacBook range, and we will not have to wait long to find out as every year Apple run their WWDC in June where new products are announced etc etc. This year because of Covid19 it will be an online event only, and it starts on 22nd June, so that will be when we can expect to get the first snippets of info about the new model(s).
I have read a small number of articles that clearly indicate that yes 32 bit apps run on the Surface Pro X without issues…
JohnW