>>now I wonder if this decision wasn't made long ago, and word was carefully leaked to various developers to get the housing ready

I don't know about this but for years now (around ten years now) I've heard about developers trying to transform locations that used to be all factories into residential neighborhoods. Slowly but surely this has been happening all along Brooklyn's riverside, which used to be dominated by factories.

[1] https://www.rentcafe.com/blog/rental-market/brooklyn-skyline...

[2] https://ny.curbed.com/2018/8/9/17667488/new-york-domino-park...

[3]https://www.wnyc.org/story/after-years-delays-sunset-park-re...