They fixed it by making everyone who completed it to never run it again. If you change a bad thing into somethin worse, why cheer?
"Oh, let's do something about preventing ppl from speed running." - "Nah, we do just something to prevent them from running it at all, ok?" - "Ok, great idea"
And you can't let just one player watch their cutscene and start running of alone. He will catch up either when you die ('cause he's tank/healer) or while you still fighting the first set of adds.
And if you start a boss fights while he's not ready, congrats for needing even more time than waiting 30s.
And the problem with Castrum/Praetorium was not speed running, it was the fact, that you could reach the bosses even at normal pace with ppl still stuck in cutscenes, lol.