I think you're off base. I've most commonly seen it used by fundamentalist sects as a shibboleth to distinguish people who know "Jesus" is a glaring and unnecessary anglicization from those whose knowledge of the Bible is cursory at best. Particularly since the "a" in "Yeshua" would need to be silent for the acronym theory to even make sense. It isnt silent. In terms of a shibboleth, keep in mind that "Jesus" in the stereotypical Western pronunciation is essentially an anglicization of the hellenized pronunciation of an Aramaic name. It's like listening to the Spanish pronunciation of "Jesus" and anglicizing the heck out of it to "Heyzoos" and then wondering why some people pronounce it differently. For perspective, the current English pronunciation of "Joshua" (yeah, the guy who marched around Jericho) is closer to what Jesus would have called himself than "Jesus". Because the anglicization is that far off. Which isnt wrong to do, it just sounds retarded to anyone who has ever heard a remotely accurate pronunciation. For much the same reason you'll get snickers if you shout "Praise Heyzoos!"