Yaz hit it on the head on this one for me. I can't call Samoa Joe a newcomer or a Rookie. The guy has been a known commodity on national/global television for 13 years. All of the other people have been known on the independent scene for a while too, to the point that when they sign with WWE the peoples on this here forum are ecstatic. Kairi Sane, Nakamura, Aleister Black, Dunne, and Bate all were discussed on here prior to debuting. Hell even Velveteen Dream was on Tough Enough and wrestled sporadically as Patrick Clark on NXT TV before becoming Velveteen.
Literally no one here said a word about Lars Sullivan before he had his first appearance after Mania. It was "who is this guy" which quickly turned into "holy shit this guys awesome". That's a newcomer, and that's my vote.