Will wearing a more supportive shoe rather than a minimalist shoe help with tendinitis/ankles problems?

Yes Rx by Podiastris: Depending on the ankle problems and tendinitis location, you need to consult a podiatrist or an orthopedic specialist to consider what kind of support you need in foot and ankle yes as a rule shoes with support are better than minimalist shoes.

I think it : Is better but an orthotic or brace may be needed as well to maximally help the condition.

It depends: Most doctors will recommend supportive over minimalist shoes. There is some debate that minimalist shoes with less support strengthen foot and leg muscles. Talk to a podiatrist, as to what might be best for you, taking into account your foot type and mechanics.