Linguistically, that seems very unlikely. The lost medial "k-" occurs preceding "-i", thus "kaku" -> "kakita" -> "kaita", but not preceding "-e"....
Corruption from "maketa" to "maeta" to "maitta" seems to me that it'd be some regional variation that achieved common use. I don't want to dismiss that theory out of hand, but I'll just say I've never seen such a theory in any of my references.
Thinkng more on it, my source was a Saito from Gifu who was uchi deshi at the yoseikan. Everyone was saying maetta! (or maita/maitta!) in practice and I had first learned it in Alabama, but it occurred to me that I didn't really know the meaning of the word and it came up as I conversed with the Gifu man.
And now as I recall, he said that the actual word was magetta, which was from maketta, pronounced magetta and shortened to ma'etta.
I would say it's Shizuoka ben but it seems to be used throughout judo and so would be likely the same word but maybe not the only form of it. I would guess it came to the yoseikan from judo, but whether Saito from Gifu was correct, I cannot guess.