AI isn't magic. You require a large dataset that's curated and well maintained and time to train the model. Not only that, osu! already has a feature on the beatmap listing page, that tries to find maps based on the star rating. It isn't the best system, no doubt, however, as osu beatmaps currently don't have description tags at all, this is the second best thing. Alongside this, since osu! beatmaps don't have tags, we will need to manually tag every single ranked, approved and loved map. Which is even more time.
AI is just an overkill solution for this problem. Adding tags to beatmaps will be great and combined with the current recommendation system, it will do what you want.