In my experience the YouTube algorithm is very easily manipulated. Just scroll through your feed and select "not interested" for what you dislike. The type of content changes very quickly.

Over the years I’ve probably „blocked“ every single term from the Star Wars universe. Yet as soon as the next iteration of the franchise approaches box offices I find myself flooded with the most absurd cross-marketing videos you can imagine. Not talking about (official) ads. I have the strong impression the algorithm either takes ad campaigns into account — or is being abused by advertisers very successfully.

Makes sense, ads are payed per impression, so if a company soaks away more impressions that don't lead to actions then that means more revenue. I guess the trick is to make sure your still - only just - the best cpm around.