In general, though, I prefer an actual text response - I won't see, or be notified, of an emoji reaction unless I go and look for it.
And sometimes "ok" can be ambiguous, too, I guess - depending on contxt.
It never occurred to me that a thumbs-up could be considered passive-aggressive (I still don't see how), but that seems like the sort of thing that is dependent on the exact social circle involved. You do have to conform to the communication norms of whatever group you're communicating with.
That's an excellent point. It does make sense to observe the way certain common forms of acknowledgement are being used within different context to understand the way that the group interprets them.
A thumbs-up can be used in a dismissive way at times. As one example, see the Giant Thumb Guy meme: https://knowyourmeme.com/memes/giant-thumb-guy.