It's just a historical oddity.

Well before it was clear that there was going to be a "MEGA" team with the
specific mandates set out above, we knew we had this big set of interrated
problems, cf-release being too monolithic, etc. Informally these set of
problems were referred to as "MEGA". The name stuck in people's heads and
conversations, as the actual name and responsibilities of the team
eventually got clarified.

It's similar to Diego in a way. Originally thought/discussed as a rewrite
of the DEA in Go, that description would now be considered misleading as
the project is so much more than that.

We're open to backronym suggestions for what MEGA could stand for though ;).

Amit