I haven't done the math and it's very possible Sony still has more games that Xbox ready for PS5 bc just based on PS4, alone. I think he may me talking about legacy--playing some of the Xbox, Xbox 360, and Xbox One games you already own on your Xbox SX (or, *snicker* Xbox SS).
Either way, we're gonna have more games than we could ever hope to play on day one no matter which console/subscription we prefer.
I did do the math, that's how I came to this conclusion. I believe it's like 2500 Xbox One games, 600 Xbox 360 games, and 39 Xbox games. The total came out to 3197 games backwards compatible on Xbox Series X, vs the PS5's reported "4000+", as has been cited by multiple sources.
As for the bolded...yeah man, this is gonna feel good. in this house, neither of us have the PS4 pro, but we both have PS4s (My launch model and her slim model), so all the PS4 games we DO have will either be upgraded to utilize 4K or get an upgrade to a PS5 version.