Well, unless they race twice at the same circuit how are they going to move to the next circuit and have the bike setup, etc completed, etc within 24 hours? Not possible, of course. But I also don't see the point of racing twice at a given circuit?
If a championship needs "X" amount of races and lets say a lot of the tracks become unavailable, then why not?
WSBK have two races in one day for instance.
And like I mentioned, I think it will be interesting to see. I think it will bring interesting data, for instance if day one and day two look similar, it will show how consistent the teams are for those given days. If the results differ greatly it will show something else, like how good the riders's race craft etc.
I think it could be interesting for sure.