When will Boot Camp start supporting Windows 11?

It's not going to happen. Windows 11 has hardware requirements that no Intel Mac will meet because of the way Apple computers' hardware architecture is designed. Apple no longer produces Intel-based computers, so they aren't going to change an abandoned architecture. And there is no Boot Camp for Apple Silicon computers...

You can install Windows 11 in a VM such as Parallels Desktop for Mac.

doubt it, they no longer sell macs with intel cpus and their new m1/2/3/4 don't support boot camp at all, so the expense of r&d & q&a for a feature that in no way could give them revenue would be a hard sell

and they had 3 years since win11 was released to make the support if they wanted to.

No one from Apple is here so no one here knows. If Apple were here they still wouldn't tell you.