Edgar, Charmed Groom vs. Minimus Containment & summoning sickness
When Edgar returns to the battlefield from his artifact state, he doesn't suffer from summoning sickness as he should. When you disenchant Minimus Containment, your creature does have summoning sickness, even tho' it was on the battlefield the whole time. Either Edgar suffers summoning sickness when he returns to play, or creatures that have had Minimus Containment removed do not. You can't have it both ways.
-
[Deleted User] commented
A permanent that you have not controlled continuously since your turn began has summoning sickness. When Edgar Markov's Coffin transforms back into Edgar, Charmed Groom, it remains on the battlefield, and transforms into its front side. This means you have controlled the permanent continuously, so it will not have summoning sickness.
As for your Minimus Containment example, it would not give summoning sickness if you controlled the permanent as your turn began, and then Disenchant'ed the Containment.