If Nvidia manages to buy ARM, this would immediately trigger regulatory scrutiny since ARM is licensing many of its IPs to an entire portfolio of companies that are considered competitors for team green.
https://www.notebookcheck.net/Largest-ever-deal-in-the-chip-industry-could-see-Nvidia-acquiring-ARM.482695.0.html
I don't think it could work like that. Any attempt of Nvidia trying to reenter the mobile SoC space by pairing their GPU with ARM's CPU could jeopardize ARM's fundamental business model. Either they buy ARM and merge the technology elsewhere, or they buy ARM and maintain completely independent operations(...then why buy ARM?) or they don't buy ARM.
Whatever happens, there must be more sustainable development with software and gaming companies, to make this ARM technology more compatible. It's amazing the battery autonomy of the ARM laptops in usage, a little less in sleep or hibernate, but this is truly the future of ultrabooks, we have reach the limits of thermal dissipation with the old school thinking of Intel, Nvidia and AMD. These laptops also benefit from great thermals, to say the least, if it wasn't for the low compatibility with software and games, I would already have purchased one. If all goes well, in 2-3 years software, 3-5 years for games, everything should be much better.