Yes twitch partners get pre-roll ads forced on them. Streamers complained about that since it might make new viewers leave the stream instead of waiting for the pre-roll to finish. So what twitch then came up with is allowing streamers to run adds on demand and then pre-rolls will be disabled for a certain amount of time, but that means they are running a lot more ads than with just the pre-rolls.

Hasan may not require 90 seconds of ads to disable pre-rolls for 60 minutes, I'm not sure how long his ad breaks are. But he is still running a lot more ads than when a streamers just lets twitch add the pre roll ads.

https://help.twitch.tv/s/article/ads-experience-updates?language=en_US#DisablePreroll