Board Thread:Questions and Answers/@comment-172.58.207.184-20200415194349/@comment-27045866-20200415195721

In an old Q&A he has said:

"4) Can widow monster find new husband?

'It is possible, but many of them remain faithful to the memory of their husband, so unless the new husband can truly express his love, and the MG would accept and love him, they will not marry. However, in many cases, the widow will try the necromancy or go to Afterlife.(But in the first place, incubus will not die so easily.) [Note: Curious on this, I asked some more questions. The form of the afterlife isn’t set in stone yet, so there isn’t a really strong image/idea for what it’s like yet. KC has notes, but they’re to be solidified later."'

This was old. He has since fleshed out resurrection magic found here.

Resurrecting men is a long and complicated process but it is possible. In general incubi are hard to kill and monsters and their husbands age at the same rate (or are both immortal unless killed if you are married to an undead). Making all of this a rare occurrence.