If Tumblr does join the fediverse and adopt support similar to Mastodon it will likely overwhelm most instances in terms of activity processing/media storage and moderation

In addition, due to their prominence they will attract bad actors leading to them blocking instances, further fragmenting the fediverse

It paints a picture where they only federate with huge/trusted instances, a curated collection of centralized instances

Hope I’m wrong, encouraging corporations to adopt warrants caution