Itch.io has RSS feeds, they're just a little hidden: add ".xml" to most URLs to get one. E.g. here's the one for physical games. Your other suggestions are interesting though. Good thinking!
Thanks for the quick reply and the info. Thinking more broadly, one of the challenges as a buyer and player of ttrpgs is finding new games that suit my taste. An approach I'd like to see a big enough site use is for me to click on a game I already know I like and find out, say, that of the 100 others who like the game, 40 also like game x, 35 like game y and 28 like game z.
It would give me a little road map to explore new games that others with my taste have enjoyed as well.