So much misinformation in this thread. Where to start.
First, we will need a LOT more than $50mil to buy the Times Square Church!
Second, nothing can be built OVER the landmarked theatres. So it is incorrect to say there will be more built because (a) there are none and (b) there cannot be a first one. If you really knew your history, you would understand that.
Third, demolition requires a lot more than paying someone off. The theatres (like Penn Station) were torn down BEFORE the extant regime became law and in fact are the raison d'être for those laws. A knowledge of history requires a knowledge of how timelines work.
Finally, there is actually an enormous amount of yet unbuilt space in the theatre district. The problem for developers is density, not ground space. Cantilevering over a Broadway landmark, even if it were legal (which it is not), is an expense no one covets. It is a lot easier to build up in solid blocks.