I don't think it is case of MLCer 'not liking' being alone. I don't think they CAN be. If they spend time alone they start to think. OP are a distraction. I know that a few MLCers don't appear to have an OP but they generally have an addiction - fast cars, motorbikes, speed boats, spending money.
My xh dropped OW1 and was with OW2 either before it ended with OW1 or right after. And yet he told me over two years ago he needed time on his own to figure things out. I have no idea whether he is with OW2 or 3, but I do know he isn't on his own, and hasn't been for an instant since he left.
And I agree with Snodderley about NC. They still think we are there. My xh was quite annoyed when I told him just over a month ago that I would prefer that he stayed out of my life and got on with his own. He has never been one to be in touch a lot, but sporadically, just to see I am still there. This story has now changed to my not wanting contact and he always wanted to be in touch [which is simply untrue!]. So it immediately became 'my problem' that I didn't want to have contact with him. An instance, according to him of my 'all or nothing thinking'. I didn't defend myself or argue, just restated that since we were divorced, and the children were grown I preferred to not have him in my life.
I feel so much better not having to deal with his craziness. It is actually quite disturbing dealing with a crazy person who tries to gaslight us all the time.