A neighbor had been feeding him and checking on him while his cat mom was gone but that is certainly not the same as having his mom around the house all the time! We’re sure he has absolutely no idea where she went!
Cats can be very much like human babies in that way. After many days away, thank God mom is home again! He hears her but doesn’t come right out to greet her. Instead, he stays in his room calling out to her.
When she arrives, it seems he has quite a bit say to her! He is clearly happy to see her, but we suspect he is also expressing some displeasure that she left, possibly!