All eFabless designs for the first two years of the program were multi-project
wafers with single-project
chips. And they still required the management engine.
Over the past year they tried an experimental "multi-project chip" (first samples shipped 14 months ago). But the management engine was a requirement long before this happened.
GP seems to have edited their comment, but I can't edit mine (even though it is only 8 minutes old)