One old geezer's reading of this:

He & his ex were on definitely non-friendly terms at the time. Later, they got over their hostilities. No implication that they are now friends, let alone in a relationship.

His ex may have been inquiring about the odd blog posts mostly because she'd have to tell the kids "your father is [in jail|dead|etc.]", rather than because she cared about him.

We actually did remarry 5 years ago.

Therapy and maturity and ditching some bad friends made a world of difference.

First successful occurrence of AI assisted marriage therapy?

It reads like he married the same person twice.

I imagine it can make the second wedding a bit awkward.

Yes, I did! Second wedding didn't have any of the awkward people present, they're gone from our lives.