I hope City never sell Diaz, that would be like Chelsea getting rid of KDB and Salah. I see no danger that Foden will leave.
Hopefully Diaz and Foden both will play the full 90min after the PL is won, if we do it earlier.
Diaz and Foden should be getting Premier League medals as a minimum. That's only 5 appearances (Foden currently on 2, Brahim on 3).
It's such a small thing, but to have the academy be able to say they've produced PL winners, to have pictures of those 2 getting their medals etc. will be a massive boost to everyone at the academy who's been slogging through these barren years.