I don't believe that 'Bob' was released from Mr. C. My impression is that Bob was on the cusp of being forced out by Mr. C's imminent death and the woodsmen healed Mr. C and preserved Bob's host. Before the 'The Return' ends, there will be a physical and allegorical confrontation between Cooper and C.
I'm personally more with the idea that Bob is supporting Mr C.
While Mr C is Dale's doppelganger, Mr C is derived somewhat from Bob. I think that while the white lodge can create life, so too can the black lodge, but only in a twisted sense.
What I'm trying to get at is that Bob is very much a part of Mr C and they have some kind of spirit symbiont relationship. As close as father and son as two evil spirits can get.
As an aside - it could be that in the twin peaks universe, all spirits are essentially one from the same single source (like puppets from the same hand). There is the black source and the white source. So when the giant "created" Laura, he was merely facilitating her vessel from the white lodge source and granting a portion of the light onto our plane in the form of Laura.
I see the same as the doppelganger creation. A single evil source, spread into multiple consciousness. Bob created doppelganger dale for his own ends but ultimately for the "good" of the black lodge source.
Just my two cents 🙂
I'm not really sure that was Bob, at least as where known him.
First, you have "the evolution of The Arm", showing the Inhabiting Spirt(s) changing, and the begging of the previous episode with the mirror science when Coop was not sure if Bob was still there
Then Cooper/Dopple Coop is acting nearly nothing like Leyland did, except when it was clearly evident Bob was in total control. Besides, where where the woodsman when Leyland died?
Alwo the Secret History alludes to multiple species, which could explain the Woodsman and the bug/frog thing. . .
Could it he that there is an additional conflict involving Bob?