I would start by culling that thousand down to a more reasonable number, something like 100 games. I’d do this by evaluating the surface level quality of the game (does it have a video trailer, are people commenting / rating it, is the page well made, are there at least a few results on google for reviews / videos made by external creators)
I have really enjoyed the selection in past itch selects bundles, where there’d always been at least two games I was interested in, which justified the purchase, and I often ended up trying and enjoying a game I wouldn’t have expected. Personally, I’d be much less likely to buy a bundle with all visual novels or all horror games, as whilst I will occasionally play these, I don’t really want to play ten of them all at once.
I also feel that what made the itch selects bundle valuable was the curation of amazing games from across the site. There are already many other bundles in the sales tab which target specific genres / creators, but these almost all lack that special curation of hidden gems you may not have found otherwise.