When I first played the chess Olympiad (in 2000), it was a 14 round event, with teams of 6 players. Over the years the Olympiad has gotten shorter (and smaller). The rounds dropped from 14, to 13 then to 11. The size of the teams dropped from 6 to 5 (in the Open), although the number of boards playing remained at 4. As compensation the size of the Women's teams went from 4 to 5, although not every country sends a women's team (although on occasion some countries only send a women's team).
For this year what's getting chopped is the number of rest days, from 2 to 1. Previously the format had been 5 rounds, rest, 5 rounds, rest, final round. I assume that instead it will be 6 rounds, rest, 5 rounds. Obviously this is to reduce the costs of the organisers, who are on the hook for players accommodation. And as a player I would not be that fussed, as my primary focus if I am in a team is playing chess (although if I was a professional I might be more concerned). But as with previous changes of this nature, it is part of a trend to reduce the cost of holding chess Olympiads as much as possible. Maybe the previous suggestion from within FIDE of a two tier, 2 round a day, 1 week Olympiad isn't that far off.