I am not disagreeing with this, just noting that this type of thing — making arguments about policy based on how business entities will react to it — is generally classified as "Economics," but when you do the same thing for voters, it's considered to be something separate.
4 (con't). IF developers expect that future politicians will put rent caps on existing units then they won't want to build as many new units today.
Even if Neale & Bharat think they're temporary and include sunset clauses etc. there is lots of history of extending/expanding.