I'm sure this has all ready been discussed in this extensive thread. Although, I read somewhere, that the new carriers will be able to embark 72 a/c maximum load.
To embark 12 F35s, increasing it to 24 supposedly for a combat operation seems like such an underutilisation of the carriers capabilities(even if its less than 72 a/c max). It sounds simplistic, but just by looking at the carriers you would imagine they could carry 72 a/c.
Anyhow, there is talk that the USMC will embark on the carriers intially. I would suggest that there may be a permanent USMC deployment onboard the carriers? I'd imagine from their and our perspective it would be a good training/operational move to be able to embark perhaps a squadron of USMC a/c alongside whatever we end up putting on them.