It reads to me that a strata manager who stuffed up with a building previously has now joined the company that came in a cleared up the mess.
If that’s the case, all you can do is arrange a meeting with one of the principals of the new firm and tell them that you are uneasy about this arrangement and why. You could certainly ask them to make sure that strata manager never has anything to do with your building and they will probably get the hint that you aren’t impressed with the calibre of their employees.
But it’s not a conflict of interest unless someone has competing responsibilities and fulfilling one would mean defaulting on the other.