It seems a bit like they're saying: "ohhhhh, did you people think we were an image hosting site? Heavens no, we're an SNS and always have been. We'll update our rules to clarify this".
They were image hosting for reddit. Once it was obvious reddit would kill their only use case soon, they became a social media platform. A better idea than simply dying. Every platform now has its own image hosting so their service was rapidly becoming irrelevant.
The big ones do. There is stil the long tail of forums and legacy chat platforms that don't do hosting or have extreme limits. That is what will be most affected by this change.
