it's certainly not for no reason, but it could be a PR move not actually backed up by good technical evidence. The public evidence certainly most strongly hints that higher core voltages could be part of the issue, but the motherboard companies responding to that by doing the obvious thing does not necessarily mean they have actually confirmed the issue exists, just that they either think it's worth doing it just in case or as a way to avoid being seen as not doing anything about it.

This is a market segment which has had many a case of mass wild speculation and theories around a small case of reported failures, and most of the theories have turned out to be wrong.