Well, how did you end up "acting as the local manager?" Were you formally assigned to a named job role? Or were you a dev who stepped up to take on management duties? It sounds (mainly because of the word "acting" with all its connotations of being temporary and ad-hoc) like the latter. (Already I'm doing guesswork and reading tea leaves, just like you seem to be in your post. Can anybody talk to each other over there, or no?)

Anyway, maybe in the eyes of management you were handling two jobs, which maybe they appreciated, but as soon as they were able to rectify this, they helped you out by hiring someone to do the managing so you wouldn't have to. If they had the wrong idea about you (i.e. you prefer managing and now want to keep doing that) then you probably need to express your interest in management and advocate for why/how the company would benefit by your doing it.

But yeah in general people have the right to a clear job description that everyone agrees on, and to be able to review various duties as they apply to that, and accept or reject them, and to modify the job description if and when applicable.