Xkit’s editable reblogs extension is having issues with Tumblr’s code, so they’ve gone back to that format for stability while they work on it. So, anyone who has that extension active and reblogs a post sets it to the old format. As far as I’m aware, at least.
Well, whatever it is, I hope it gets fixed soon because they’re making the mobile app a huge hassle again, especially with the really long posts where it’s nothing but those horrible lines