K,

"When a spouse has left us, abandoned us, separated their lives from ours, and ESPECIALLY when they have chosen to involve themselves with a new person in ANY capacity...well then the dynamics have changed."
Isn't that generally the case with most of the WAS? And I really don't see that he has "abandoned" you.

"None of this means that there is no chance."
If you keep the expectations the odds are slim.

"You will have to tread water waiting to see if he ever comes around to becoming interested in you and willing to reach out to you. How long can you do that?"
1, 2, ... 63, ..., 69, ... ,100, ... (I'm not holding my breath, just trying my best to be sarcastic for once).

"But I reject the notion that this remains YOUR job to save."
Given the 'sitch' who else is capable of doing this job!?