Anyone that thought Baldur’s Gate 3 would just automatically release on Linux because it was releasing on Stadia was just delusional. Larian Studios didn’t even support Linux with Divinity Original Sin 2 despite supporting Linux with Divinity Original Sin… why? because they learned their lesson which is:
The biggest issue with releasing any software on a particular platform is whether there is enough potential revenue to make a profit over development and support costs. The only reason BG3 was announced for Stadia was because it had the backing of Google and could deliver up-front revenue to help offset any cost concerns while Larian worked on developing and supporting for Stadia, a fixed platform, that had a finite support structure.
If Stadia did well, larian studios might have released on Linux, but when Stadia tanked, so did any idea of there being any hope of a release for general Linux.