So basically what this is going to mean is that somebody can spend hours and hours putting together a post, and when someone reblogs it and adds anything at all to it - even if it's just an applause gif or a single emoji or word like "gorgeous!" on an exceptionally stunning piece of art - each of those reblogs becomes its own post, and none of the likes or reblogs that come after will trickle up to the original creator.
It will also mean that if someone has something hateful to say, it will not get back to the original author and they will not be able to respond or clarify or set the record straight. It will make it so that someone can reblog a post and turn it into a vehicle of hate against that original creator, without any recourse for that original creator. It will lead to more toxicity and ridicule and hate on the site.
It will mean that if somebody downstream reblogs a post of mine with a question about some aspect of what I said, I will not be the one answering that question because I will have no idea that it was added.
It will also mean that if someone reblogs a work of art and adds a meme of someone weeping for joy at how beautiful it is, and then that gets reblogged and liked a million times, the original creator will not get any of those notes, and the original post on their blog will still only have 20 notes even if it becomes the most popular piece of art on the entire site.
This is going to utterly obliterate any sense of community that came from engagement with a post. Every reblog that adds anything is going to become an amputation of that post, and a creator will have to actively crawl down every separate reblog chain of every post if they want to try to find out what's happening with their content.
Just FYI everyone, because of this change I will be disabling reblogs on posts where I am sharing my own thoughts and ideas. If it's just a photo set or something I will not disable them, but anything else is going to get disabled because I do not want to feel like I'm putting my work out into the wilderness and have no meaningful way of tracking what's happening to it, and have a reblog suddenly turn it into somebody else's post, and any further engagement go to them.
Because let's be realistic, no one's going to go back through a reblog chain to interact with previous iterations. All of the engagement is going to stick with the current version that is in front of someone, which is cut off and separated from the original creator. If for no other reason than that no one will understand how this new system works, and they're going to (understandably) use the site the same way they always have and expect the same results.
I can think of so many ways that this could be weaponized and used for harmful purposes, and that is the very last thing we need in a world where there is already too much hostility.
Even if things are handled in a well-meaning way by people, it would still make it difficult, if not impossible, for creators to have any ongoing involvement in what happens to their own content once it is out in the wild, and will potentially cut them completely out of the conversation.
If you are as horrified by this change as I am, please do not stay silent. Please give some strong feedback through the feedback form so that the staff can realize how hated this change is.
This is one situation where leaving a comment or re-blogging with complaints is not going to be enough. Please send direct feedback about this to the team through the feedback form. They have said many times that they do not read the comments of their posts. If you do not give actual feedback in the feedback form they will not see it.