Egg nog is actually something that was traditionally drunk in Britain (and elsewhere in Europe - Advocaat, the best known brand of bottled eggnog, is Dutch I believe), but it fell seriously out of favour about 20 years ago when the country had a bad salmonella scare. A large proportion of British people now simply won’t eat raw eggs in any context - even though, as you point out, British food regulations for chickens are now extremely strict by international standards, largely as a result of the self-same salmonella scare.
My grandmother used to make egg nog and it was very much a Christmas drink for us (well, for me it was the kids’ version, an “egg flip”, which lacks the alcohol), but we stopped doing it in the early nineties and I only persuaded my family to revive the tradition a couple of years ago. Even now my older relatives will only drink it if it’s got LOTS of alcohol in it, which they reckon will kill any possible infection in the egg; I suspect they’re wrong, but can’t complain about the extra measures of brandy…
