Coincidentally, Cooperator News just published an interesting article on this subject at https://cooperatornews.com/article/the-board-approval-process

Some quotes:

"Boards can demand troves of personal information from buyers, and can approve or deny a purchase for just about any reason--or no reason at all--but they may not engage in illegal discriminatory practices."

"Unusual demands aside, most boards are primarily looking at the purchaser’s financial profile when assessing their application. Can this person afford to buy the apartment and cover the monthly carrying costs? Do they have the resources to pay a special assessment, should one be necessary?"