Remember it's federal land, so they can't be held to state permitting or building codes, etc, only what they choose to (IE if their agency adopted it explicitly)
Having seen lots of datacenters constructed over the years - it's tractable in terms of the bureaucracy parts if they want it to be - because they can mostly ignore them.
So for me it breaks down like:
Building construction, it could be done.
Power provision - hard to say without knowing the sites. some would be clear yes, some would be clear no. Probably more nos than yeses.
Filling it with AI related anything at a useful scale - no, the chips don't exist unless you steal them from someoene else, or you are putting older surplus stuff in.
Ie: making a new data center is easy. Making new power plants quickly - not so much. But hey, at least there's some renewed political will, better than nothing.
As another data point, Apple has been doing 100% renewables for their DCs since 2014. A wind farm can definitely be built in months, and energy companies will always follow the money. Site selection will definitely take energy availability into account as well.