Ggirl, Perhaps they looked at all the information on your DS and decided he was worth offering a place after all that.
The difficult question for him and you - is this still what he really wants or has all the stress of the last week changed his mind?
I'm not surprised he's muted, it all sounds very stressful.
I know my own DS1 gets stresssed sometimes because he worries that he might have a view on what he really wants which his parents or grandfather aren't quite prepared for, and he is anxious that no one gets upset.