So this is step one and they intend to sue for more and more with the Epic endgame of getting the Epic store preloaded on iPhone? I look forward to the never ending news cycle.

They don't want the warnings from Android yet don't want to put the work/money in to build their own OS, even using AOSP (Android Open Source).

If Google's work on Android entitles them to be the only store on all Android-derived devices, what rights do Linus Torvalds and all the other Linux contributors have? Or is Google allowed to monetize their work for free, but Epic isn't?

Both companies contribute to the open commons with open source software and sponsorships.

I think the right for Google to monetize and place restrictions mainly centers around the Play Services which are all tied back into their non open source projects.

You could probably make a reasonable argument that Play Services are specifically designed to undermine the spirit of open source, but theoretically you could build an alternative, and use AOSP however you wish.