I disagree with almost everything in this comment.
Unity and Unreal do not only exist for their multiplatform target, but because they are premade engines to make games with in general. Many games made with them support one single platform.
There is absolutely a commercial incentive to release Linux games. Developers would not do it otherwise, or at least they would have stopped after one try. They did not.
I highly doubt that Blizzard supports MacOS out of goodwill, and I doubt even more that if it was based on that, they could easily continue doing so after a cpu architecture change. They'd have to port whole custom engines plus middleware. That would not happen in that case.
One thing I assume is correct: If there is money to be made here engine developers and game developers will make it happen. But I don't see why it would be that easy.