I have no idea what blizzard is trying to do with Living Bomb. If they really want it to be a viable option... ever, it needs to fill a niche of some sort. In general, FB is best for adds and NT is best for single target or at very least I assume that is what they intend. LB is currently mediocre in both so its never chosen. So why are they trying to remedy this by turning it into a less frequently ticking NT with a light pat on the face at the end? I just don't understand. It doesn't need its damage shifted; it needs new mechanics. Maybe it spreads on explosion so everyone can use it like fire did in 5.1. Maybe the explosion is buffed to something respectable that is still under FB and the explosion damage doesn't affect the debuffed target. Honestly, I don't know how to fix it but I don't think this change is going to make it more appealing to anyone.
On another note, I'm glad they are finally attempting to address our AoE.