Yes, turbine blades can introduce radar clutter and affect certain military systems; but this has been know since the 1990s and has been engineered around for decades.
China, the UK, Germany, and Denmark operate gigawatts of offshore wind in close proximity to military-grade and NATO air-defense radar without much issue...
There could be new developments in the problem. For example, small scale drones using these areas as entry points. Not to say that's that, but I think it's not impossible that something new is being taken under consideration.
Under other circumstances I might be inclined to give the benefit of the doubt. But when's the last time we saw any action from this admin that wasn't clearly self-dealing or ideologically motivated instead of science-based?
China, the UK, Germany, and Denmark operate gigawatts of offshore wind in close proximity to military-grade and NATO air-defense radar without much issue...