That is plausible for some cases, but this explanation doesn’t account for all instances. Many of the pseudo-christian/hebrew names we recognize appear to be identical to their original Semitic forms, not their Ethiopian Christian variants. EC names were actually from Aramaic, then rendered in Greek before being introduced to Ge'ez. For exemple, Eli (Celi) and Simon (Shimcoon, as noted in the FAH) are much closer to the Hebrew/Aramaic originals than to the forms used in Ethiopian Orthodox circles.
When I say I believe there's something judeo-christian that's completely unrelated to the Highlanders' I really mean it