No, they knew about the cuts long ago but simply chose to keep showing unrepresentative footage of the game without disclosing it as such.
As for the "all developers do this", show me another game where such a massive downgrade was kept secret right until a couple of weeks before release. One.
The message from From seemed fairly consistent starting in ~mid January.
They began only showing footage representative of the console retail release. There are some inconsistencies, but these seem to mainly stem from ignorance or oversight on Bandai's part rather than a malicious effort to trick the consumer.
The main problem is journalism outlets still showing TGS footage up until ~February, but, again, that was probably mainly due to ignorance than anything else.