For those complaining that there isn't the full core books – take a look at the Level Up A5e ruleset. It's still core 5e but with tons of stuff going on and with a very dedicated development team:
https://foundryvtt.com/packages/a5e
I think this is outstanding news. It's one of my "little candles" that light up or go dark depending on whether Hasbro's behavior is helping or hindering the larger 5e TTRPG hobby.
By supporting Foundry, they're spreading D&D to platforms beyond their own including Roll20, Fantasy Grounds, and now Foundry. I think we would not have been surprised if Hasbro said "yeah, the digital version of 2024 D&D is going to be only on D&D Beyond, Maps, and the 3d VTT". So seeing that they are indeed supporting what we might consider to be their digital competitors is fantastic for the hobby. It means we get to enjoy D&D on the platforms we prefer or the ones in which we've already invested significant time and money. We get to choose the platforms that best support the game we want to play.
On hearing this, I started spending a fair bit of time with Foundry and it definitely has a steep learning curve. I can tell why people love how extensible it is and how seamless it can make a game with dynamic lighting, system integration, auto-assigning damage and effects and all the rest. Very cool. But probably not for me. I love to have my tools separate so I can use the right tool for the right job and switch out as I need. For me that's Owlbear Rodeo and Discord with some other basic tools (good old BBEdit to handle initiative, damage, and theater of the mind combat).
Clearly releasing D&D content on Foundry helps Hasbro – they get to sell on lots of platforms. But it also helps
us because we get to choose where we buy it based on our own preferences. I'm very happy about that.
I also think that Foundry is a touch more resilient than pure online only platforms like Roll20 and D&D Beyond. If you buy a module for Foundry and download it – you have it. It doesn't phone home except for updates. If you run it locally and then move to a Foundry hosted service, I believe you get to move your license keys with you so you can actually run it on multiple foundry servers. It's not pure full interoperability but it's not too bad. It's still not very practical to say you can keep playing with whatever you bought forever but it's not bad. Foundry is different that way since you're running your own server or paying for someone to host your server.
Anyway, I think supporting Foundry is outstanding news and I applaud Hasbro/WOTC making the choice to do so.