I'm aware of those things, but are those the reasons? Are they actually planning on moving away from their existing audio, networking and threading solutions and switch it out for SDL's implementations? Are they planning on porting Minecraft Java to platforms GLFW doesn't support?
A little AI assisted digging indicates SDL3 has better support for switching between keyboard layout keys and physical keys depending on context (ie. Game controls can be WASD or whatever letters those physical keys are while it can use international keyboard layouts for chat boxes).