That is the important question imo, who is this previous developer?
It's not clear that it had a previous developer. The site was run as a technical training centre owned by the UAE (something to do with their their military apparently, but that's not clear). It's not been used for a few years but still had security on it, apparently still employed by the UAE. It seems to have been the security guards who've told the locals (in May 22) that it was being sold for an asylums centre. The August 22 sale date could have been the finalisation of that purchase.
The site's allocated for a 140 houses with 30% affordable on the Local Plan for the area.