That’s going to be the case for all Valve games at this point. When Left 4 Dead 2 released back in 2009 I was 18 years old. The 2027 graduating class was born between 2008-2009. So hypothetically, anyone who had a kid in my class right after my graduation would have grown up playing Left 4 Dead and now their kids would be playing it.

Aside from Alyx, I highly doubt we will ever see any new major titles with the their older games at this point.