What the hell else is he going to say?
Are you implying that he just said it to appease Manbeck and Angel still might leave?
I think at this point its pretty definitive. Granted he could do other things, but there is only a month left in the late signing period, so Angel is running out of time if he wanted to leave. He'd still need to finish the process to get released from K-State, then need some time/weekends to visit other schools. Plus I think Art has a lot of sway and if he says he's staying at this point I'm pretty certain that is the case.