From the stand point of the original language of 2 Cor. 5:17, your rendering is grammatically highly doubtful. The word is actually, KTISIS, a masculine adjective "creature." The only antecedent of a masculine gender anywhere nearby is "any man in Christ." There is no verb "has come" in the sentence which would be necessary for your translation. As a matter of fact, there is no verb in the first phrase at all which often indicates "to be." Interestingly, this phrase echoes a common slogan used by Jewish rabbis when someone was undergoing the initiation rite of the Jewish faith. "He who brings a foreigner and makes him a proselyte is as if he created him." Paul would have been very familiar with phrase from his former life.
Actually Jack, ktisis is a feminine noun from the root word ktizō. a verb. The connotation is of creating some THING, NOT someone. This should be clear for anyone who says they have a degree in NT Greek.
Paul is addressing Corinthian Gentiles and would not be using Jewish vernacular or sayings to communicate about their salvation. His audience would NOT see your imposed inference.