The Oxford owned CTT and the whole Brookfield Place co-ownership was a bit of a fiasco which saw people fired. Things may have changed but when it happened I'm almost certain the Oxford had the right to block or JV the development if it came to pass. Like I said, I don't know if it is still the case but I could find out.
REITs are highly aggressive in BUYING real estate, not aggressive in selling and like I said, development is capital intensive and when you have to distribute the vast majority of your funds from operation, development is a cash drag which is very difficult to manage. Allied and many others also have articles in their REIT charter which preclude over a certain % of their holdings to be properties under development. I'm fairly certain that AP could not do ALL of those buildings at once.
Menkes co-owns One York with HOOPP.