That's a good sign it means he's in the transitioning phase and behaviors may change! This to shall pass.... I have a four year old and trust me it's been hard with tantrums and had to read how a sibling might feel as they start realizing they won't be the only one! You just have to love them anyways and reassure them when your family grows your heart grows just like when they love one toy they can love another!!!
Yes! That's normal for kids to act that way. Some kids are different, some are very clingy and some just don't want to be near you what so ever. No need to worry, everything will be okay (: