I don't know. If Microsoft didn't do this then it would have been someone else because music, movies, and television has gone this route. Hell, even software in a lot of cases. This is where not just the industry is headed but most all forms of media, so instead of being fearful of what it would mean down the road, maybe just embrace it for what it is. I can tell you that because of Game Pass, I have tried and beat a ton of games that I'd never have given the time of day to because there was a monetary barrier for entry that I wasn't willing to pay in order to simply try the videogame and see if I liked it. And many of those games I ended up buying DLC for, etc.
Forza Horizon 4 was my first Forza Horizon game. MS included that with Game Pass and to date I bought all the DLC and car packs for it, that's money MS or the dev never would have saw from me had it not been for Game Pass. The idea of an open world arcade racer was not something I was interested in until I could play it for free and realized like "holy shit" this game is amazing. 200+ hours later and $60+ in DLC and car packs, and I'm not doing the same with FH5.