I think that a lot of kids are indeed affectionate and this is family. I'd not worry about that. If he does this with say . . . strangers? Then yes. It shows a child who may have a developmental issue and doesn't know close circle-- okay to hug, kiss and not in my circle--- not okay to hug and kiss. That's not an uncommon thing in kiddos that have neurological differences. My son is neurodiverse and as a youngster, he did occupational therapy. They did an activity with him where they had pictures. Pictures of family, friends, neighbors,strangers, teachers. Then he would put the in categories Who would he hug/kiss? Who should he give a high five to? Who should he just say hello? It was helpful.
I don't know if you should be worried, some kids are just impulsive and they are just a lot less bothered by what others think of them at that age, which is usually nice for them but not necessarily for others. So you probably should stop him from doing it just given covid, if nothing else.