If their ARM processor is used similar to how it is in the iMac Pro I would have no issue. If they move from x86 I will simply not buy another Apple Mac product, simple as that. People love to chime in that the migration from Power to x86 was easy,. yes and no, it all depended on what you wanted to run. The difference being that it was accepted people wanted x86 compatibility because all the doors it opened.
plus I really don't want to end up in a situation where the app store is the gateway to apps/programs I want. because you know damn well they will go there all while hiding behind protecting their customers.
the game market is already thin for Mac, going ARM would me the chance of a PC title coming to Mac being about nil. Really don't like the idea that my options would effectively be reduced to Candy Crush type crap. PC gamers make fun of Mac already... can you imagine? hell I would join them
iOS has almost all the Final Fantasy and Dragon Quest games. It also has Final Fantasy Tactics. Monster Hunter Stories, Civilization VI, Xcom Enemy Within, Star Wars KOTOR, Life Is Strange, Baulders Gate, Baulders Gate 2, Icewind Dale and Planescape Torment. I know these are old games but if they can be ported a more powerful ARM processor be it iPad and/or Mac could run even newer and more intense games. I think it will be fine.