[davem]

Based on this understanding, Morgoth must therefore be the one to be honored as the creator of all good and glory, etc. Obviously this is not the case. Rather, this is another example of a eucatastrophe, an unforeseen (amazing) grace brought about against all odds, and certainly against Morgoth's calculations. One must wonder what kind of thinking is at the back of attributing goodness and self-sacrificing nobility to Morgoth?

I don't see that it does require Morgoth to be honoured as the creator of all good & glory - which he clearly is not. Prometheus does not create the Fire which he steals - he merely steals it & makes it accessible - which is what Morgoth does. It merely argues for Morgoth's necessity, & refutes any claim that he is not necessary & that Arda could have done without him.

Without Melkor nothing could have happened - & its certainly arguable that without Melkor's dissonance there would have been no creation of Arda at all - if the Music had been played aright in Eternity them why do anything with it - why give it form & make it 'real'? Morgoth's rebellion is necessary for there to be something rather than nothing (or at least something interesting)

Since Tolkien does write Morgoth's exile into the Void into the story, why does this occur? What would be the results of this not happening?

Well, Morgoth must be 'removed' - but the point is he is not removed from existence altogether, merely removed to a place where he can do no further harm - one has to ask why he is kept around & not removed from existence altogether if not so that he has a chance to return to his original state.

Back to the original point though - it is entirely possible that it was Melkor's destiny to be the object of honour & glory - what we see is not him acting entirely out of his true character, but him acting out his true role but in a perverted, broken way.