While it is true that the org could tell them that they needed to sell or not, they local body had a lot of input as to what they wanted to do.
While true in theory, most body's would do whatever the org told them to do, without question.
One congregation I attended, although the RBC dictated that a new KH was to be built, many in the cong were openly against building a new one when the existing building wasn't overly old and could be updated at far less cost. This was a cong which frequently had difficulty paying the monthly utility expenses, never mind a large WT mortgage.
While there was a vote with a small majority favouring renovating the existing, the elders wouldn't pay heed but instead stated that as the RBC said a new one was to be built, that was how the matter was to proceed. Virtually all of those elders moved away to other areas soon after construction so they didn't contribute for long financially, if at all.