I'm curious as well.
If there are really a bunch of polygamists in the quorum of the 12 then im shocked I have never heard about it before.
This. I'm not really pro-LDS after this little stint, but I'm curious.
Do you mean a sealed wife died, and then he married another in the Temple? Wikipedia doesn't mention an unsealing, but such things are sacred, and not mentioned often. This would mean, theoretically in the LDS cannon, this man will have two wives in heaven.
https://en.wikipedia.org/wiki/Russell_M._Nelson