I can't imagine choosing a groupset purely based on which one I can get first. There is probably going to be some difference in quality or features between DA and Red.
If I were you, I'd get any groupset I could for now, wait until details about DA dropped, order the group I really wanted, then sell the old group once I got the new one. Even used R7000 should be good enough as a stop gap. Of course your new bike won't feel as nice and shiny as it would if you went with a top tier group but... that is my opinion.
From what I know, shimano releases have always been extremely delayed. They'll announce something and then take ages to actually get the supply chain moving. Especially now that covid is a thing. I talked to a couple bike shops and apparently shimano parts in general are in short supply even now. They told me to look online.
And 12 speed DA is probably one of the most hotly anticipated groups ever. I wouldn't even count on getting it before September.