I agree with your reaction. They shouldn’t be telling him and he should have hesitated to repeat it. Apparently his nightly viewership is about 300,000 so it’s not like he announced this to a small select group.
Of course Iran knows about our build-up all around them, and non-Emergency personnel are being told to get out of the region. In that sense the possibility is common knowledge.
If it doesn’t happen tonight then his revelations become less credible in the future. Maybe someone speculated to him that we would be in a position to do it starting tonight.
How much air defense could Iran have rebuilt since the 12 Day Way 8 months ago? We know Russia doesn’t have much to spare/share and the Chinese stuff didn’t make a difference in Venezuela.