Uhh, I'm not sure I understand. To make all "modern Jews" "traditional Christians", you would have eliminated Judaism as a separate faith. I also suspect that the many if not most cultural traditions associated with orthodox Jews worldwide in OTL (dietary restrictions, circumcision, etc) would be also reduced or eliminated - or at least not associated with "jews" as a separate faith or ethnicity.
It is also interesting to speculate how Chistianity would have developed in a world where it would no longer have to explain away why the very people chosen by God continued to reject its Messiah.
Assuming some traditional non-trinitarian Jewish believers still exist when Islam develops (assuming Islam develops), it may attract many more of these folks