As to the penalties for this; check Appendix A to Title 31 (Code of Federal Regulations), Subtitle B, Chapter 5, Part 501.
Fines can be up to and including the financial amount found to be in question. And this can be affected by; wilfulness, recklessness, pattern of conduct, managerial involvement (amongst others). Could be up to millions.
A criminal conviction may be up to 30 years in prison.
So the choices are a) follow the rule of law, or b) face years in court and possibly go to prison for 30 years. And for the later, to achieve what? Those people will never get back on the list (while the sanctions are in force) even if Linus "stood up" to the US Govt.
As the prayer of serenity says "Give me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference".
Getting sanctions overturned can be a good thing if they are unjust (and I personally can't see how these sanctions are unjust), but keeping someone as a maintainer on the Linux kernel is almost certainly not the way to do it.
If YOU want to do something about it, then fork the kernel and invite those people who have been removed as maintainers to join you.