I don’t know.  If they own the easement and are legally able to negotiate a temporary use agreement with us, there is nothing to say that they could not enter a similar agreement with another party.
Whether or not the indentures address this irregularity has yet to be determined.  There may be a stated use for this land, e.g. for a only an alley.
There could be a stated use for that land in the indentures.
This is a good follow up question and maybe one for a lawyer representing the residents.