Sweeeeet! That is what he has been needing to do for many years. The "community" of "operators" has always been pretty small, no reason why they would not have, after an entire career, knew of each other.
i don’t see the big deal here. most of the same cast is usually in all of the books. Ryan, Clark, Chavez, Mary Pat, etc... they’re all in Cardinal, Sum of, Clear And, Debt of, Execu to some degree or another. I guess teaming Ryan with his son is new. But Jack Ryan is now an ex-President and likely over 60. I can’t imagine him going into the field or anything. I suspect he’ll be more of a player behind the scenes, using his contacts to help out the guys in the field. He’ll probably have some meeting with his old KGB buddy who’s now the President of Russia or something like that.