Agree, and this goes along with Twitter's desire to curate feeds by showing, for example, tweets that were 'liked' by people you follow. By doing this, they broaden the amount of content they can show you and therefore increase the discretion they have in surfacing content they want to spread. (It's also super annoying — I follow someone so I can see what they tweet and RT. I do not care one bit about the things they like.)

Hidden downvotes are the flip side of the coin — instead of being used to boost the spread of certain tweets, they can be used as an excuse for why certain information is hidden.

Basically, these changes remind me of p-hacking. As more variables are added, you can figure out ways to structure your algorithm so that you promote the information that you already wanted to promote and demote the information that you wanted to hide. This could be for profit-seeking reasons, political reasons, or other reasons. In any event, it decreases transparency and reduces trust in the systems.

edit: added last paragraph