Ignoring the actual content and the fact that PHP 8 runs 5.6 procedural code just fine (unless it's broken code that needs fixing anyway), the part that caught my attention was the subject line and salutation.
There's something kind of adorable about him thinking that PHP is a 1-man effort and Rasmus is just sitting at home banging away on it all by himself.
I'm about 80% sure that what he really meant to write was "Where did the old mysql extension go?"
This is not a well written question by any standard. Even allowing for the likelihood that English is probably not his first language, it's just really really low effort and doesn't bother to show any work done before hand.
@kboyd Names, email addresses, and anything that can be used for identification are always changed in these posts. #noDoxxing
@pollita still, I'm impressed he was able to get a real, working example.com email address.