AWS definitely has offices and employees in California. The enforcement is not about where you're headquartered but where the employee is determined to be working. An employee living full time in California would be protected.
For agreements entered into after January 1, 2017, California Labor Code Section 925 clarifies that employers may not require employees––who primarily work and reside in California––to agree to forum-selection and choice-of-law clauses that select non-California forums and/or laws, unless such employee is “individually represented by legal counsel in negotiating the terms of an agreement.”
The same "not necessarily" would presumably apply to the choice of law clause as well, for example if California decided they didn't want a company attempting to evade their laws with such a clause, which presumably would be at the discretion of a judge who probably isn't too fond of that behavior.
Disclaimer: Not a lawyer.