Son age regression after adoption

I have been fostering my son for 2 years. Rights were finally terminated and he's been adopted. He is 6 and since the official adoption I feel like there's an age regression. He came up to me with his pants around his ankles and toilet paper and said "Mama! Can you wipe my bottom!" He's been doing things like this and behaving almost like a toddler. Is this normal after an adoption?