Obito was using rikudo chakra.Obito and hogoromo both showed that it was possible for chakra ghosts to appear in the minds of others. Neither sasuke nor kakashi were jinchuriki yet this happened to them.
Still the point remains, whether naruto was made a jinchuriki or not no one would have attacked the leaf.
Yes it turned out that way at the end but based on what minato knew the prophecy made no mention of the child of prohecy's relationship with the tailed beasts. It is for this reason that Jiraya initially thought that Nagato or Minato were the child of prophecy.
Sasuke is an reincarnation who shares ties with the sosp.
Neither Kushina nor Minato are capeable of that.
Your point is on the basis that Kurama would still be under the control of Konoha, correct? If not then it does matter if Naruto was a jin or not since he was the only one who could hold the bijuu at the time.
Give it to Kushina and she still dies it re-spawns somewhere else.
Give it to Minato....wait you can't give it to him because he could only hold half at max. So Kurama free to cause more issues and weaken konoha more and then kill Naruto and everything else he wants.