Rawthumb -
No, I'm not and have never fished the San Juan. ( Don't even fish San Juan worms, for that matter. )
But I did google San Juan River and looked at the websites of a couple guide services down there. There are folks fishing it since it came up to 4000 CFS, just using different approaches than when it is at the low flows.
Also, I think it would be highly unlikely that the BOR could get away with anything that would jeopardize the fishery or fishing the stretch of water below Navajo dam, even if they wanted to. It would cause a water war of a different kind, and it would be messy.
Suggest you contact a couple of the guide services to see if what they are recommending during these high flows is a kind of fishing you enjoy. If it is, go to it. If not, there are lots of other places to fish that time of year.
Good luck and good fishing.
John
The fish are always right.