Yes, this is what I was alluding to. The exiled Jewish elite in Babylon gradually assimilates.
Meanwhile, in "Palestine", the remnants of the two Jewish states - Izrael and Judea - worship "in high places". Without royal patronage there are no "main temples" - like those at Samaria and Jerusualem - so there is no usurpatation of "one and only place of worship" in the grubby hands of the priesthood from the capital cities.
As the Judean elite which - in order to prevent (retard?) assimilation moved from monolatrism to monotheism - stays in Babylon, the Judean variant of Yahwism may never become monotheistic. I've no idea how the Izraeli variant of Yahwism moved into monotheism - maybe somebody else could shed some light on it. Mimicry of Judaism?
So, a different Judaism - which might never develop messianism, plus there probably would be no ferilisation of ideas from Zoroastrism - and no close-to "universal" Hellenistic culture - e.g. no Septuagint to reach out to Gentiles, there is no Christianity.