What I was pointing out is not that the flight number changed, but that it changed to a new number range which AFAIK has not been used before.

I checked several dates around my flight date and they all show the new 2000 number and the A/C as an A320 (unchanged from before).

My thought/fear about this being some form of placeholder is that if this is preliminary to a downgauge like to an RJ, I may lose my F seat (not, for this route, a big deal, but it will be the end of a 20-hour travel day and every little bit helps!).

Has anyone else either seen this number range (2000-2049) used before or seen it occur as a preliminary to a later change?