If articles on HN are any guide, CEOs say this up until the moment that layoffs occur. It goes something like "while we had hoped and worked to avoid impacting personnel, changes in the macroeconomic conditions have made it impossible for us to..."

He was probably lying.

From your other posts I surmise you know this, but the WARN act means that a company of Twitter's size can't lie about that, at least without then paying out a full notice period to all affected workers.

Every CEO I've seen oversee layoffs has maintained that no layoffs were planned until the very millisecond they're announced. I think of CEOs like I think of the WH press secretary - paid to propagandize.