I would honestly make sure you've exhausted all alternatives on your IT's side. Methods to "undo" your problematic compatibility view settings is not fool proof. Even with the right meta tags, there will be edge cases that can still fail.
Not being able to get "in" is not caused by trying to override and supply these meta tags. You would have faced this issue irrespective of this change, and highlights the issues that going down this path will introduce, that I was alluding to.
Are you facing an issue at the login screen itself, warning you of an unsupported browser?