A few quick comments on this story:
i) Apostasy is always sad. These converts are repeating the error of the congregation in Hebrews. And they don't even have the extenuating circumstance of persecution to mitigate their guilt.
ii) It's quite possible to be both a Christian and a Jew. After all, most all of the NT writers were Messianic Jews.
iii) But to the main point, this parallels Catholic conversion stories about "coming home" and being "deep in history." Only here it's used to justify conversion from Evangelicalism to Judaism rather than Catholicism. That illustrates the promiscuous logic of the Catholic conversion narrative.