European licenses have expiration dates and upon renewal you will be issued the new "flavor of the day" being JAA, EASA, EARSA or UPMYARSA.
This will now void their US 61.75 certificate.
A UK PPL is not going to expire but if the 61.75 has the same restriction of only being valid for non EASA aircraft it will be as much use as a chocolate fireguard.