This is exactly what happens. What's worse, I thought it was doing that because I had responded to some political post, but FB just sees "you engaged with person-X, I will now alert you when person-X posts, and when people respond to his posts, even if you haven't looked at it"
This led to increasingly divisive messages literally showing up in my notifications that I had nothing to do with. This still happens months after I stopped responding to any of those messages.
Ye FB does something like this. I hate "funny" videos where people hurt them self. But somehow FB thought my annoyance with them was that I liked them, so they spammed them on me. Maybe I moved my cursor to slow over them or something when I took my time to mute the guy posting them.
The same is true for YouTube. Somebody sent me funny cat video which I don't usually watch, and now my feed is full of funny videos, or I quickly searched some Minecraft guide for a friend (which I don't play), and now I have many Minecraft guides in the feed.
This led to increasingly divisive messages literally showing up in my notifications that I had nothing to do with. This still happens months after I stopped responding to any of those messages.