I've contacted two creators I subscribe to whose videos suddenly turned to streaming files recently.
They had no idea about the change. They were not informed about it by OnlyFans.
I explained, politely, that the change to DRM streaming video was having a negative impact on video quality and playback, and would likely cause me to drop my subscription, unfortunately.
Both creators were totally happy to turn it off, so the videos on their pages returned to being regular video files.
I've also seen other creators I follow post that they've been informed by their fans about this, and have also turned off DRM to accommodate fan requests.
Most creators I've encountered seem very reasonable about this.