Is there a name for the fear that watching a random video on YouTube will cause YouTube flood your 'recommendations' list with similar videos?

There should be.

For example, that one video I watched about a boat getting swamped by a monster wave was pretty cool - but now half of YouTube's recommendations are about boats, ships, sailing, oceanography, etc., and I just don't care about that stuff. I can tell YouTube to not recommend them, one at a time. But that's a drag.

Likewise, clicking an item on Amazon out of curiosity leads Amazon to start recommending everything related to that item.

It's like that time when you were 13 and you made an off-hand remark about thinking that one song on the radio was cool, and then your aunt gave you records from that band every birthday and Christmas for six years.

You should be able to casually look at something without being tagged as someone who needs to see a dozen more examples of that same thing.