Re: You mess with the GNU ...
The licence clearly says:
"You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License."
If he's considered to be "sublicencing" the kernel GPLv2 code that he based his work on (by charging a subscription for a GPLv2-based work and cutting people's subscription to that if they exercise their given rights under the GPLv2 granted to them by the Linux kernel licence AND his modifications that must be GPLv2 too), or distributing it under some other scheme, then he's in breach of the licence.
It would be up to a court of law, but it's quite clear that he'd lose. You can sell it. You can't stop people who buy it from giving the source code away. And by imposing an outside restriction on a future subscription service based on you NOT being able to legally exercise the rights under GPLv2, then you are clearly modifying a contract with an external factor... which could be considered sublicencing by imposing foreign clauses not written in the GPLv2.
He wouldn't win.
P.S. you can't relicence the kernel. Hundreds of former contributors are dead and you'd need to trace every line of code they ever wrote and replace it with similar code under the proper licence. Additionally, there is absolutely no desire within the core kernel community to do so, there's a reason that "V2-only" was specifically chosen, they could have just used v2 which would allow a free "upgrade" to V3 at any point, but they specifically and categorically chose not to.
Plus, there's no need to. Nobody has ever proven a GPL weakness in any court in the world, and places like Microsoft, Google, IBM, etc. run in fear of the damn licence if they might be found to be on the wrong side of it. That tells you all you need to know.