It doesn't depend on beliefs about the true nature of mental disease.
Just a tiny correction here: CBT and TEAM both have the underlying assumption that your thoughts shape how you feel, which is an assumption about at least a part of the cause of mental diseases.
If you thought that for example depression was always just an imbalance in your neurochemistry, you'd never do a talk-based therapy and instead would focus on antidepressants.
Otherwise, I think your description of TEAM is spot-on.
Just a tiny correction here: CBT and TEAM both have the underlying assumption that your thoughts shape how you feel, which is an assumption about at least a part of the cause of mental diseases.
If you thought that for example depression was always just an imbalance in your neurochemistry, you'd never do a talk-based therapy and instead would focus on antidepressants.
Otherwise, I think your description of TEAM is spot-on.