From what I have gathered instead of explosive as an element weapons that do explosive damage now just have splash damage listed, I do think it is a nice change because we can now have explosive weapons that deal elemental damage.
There is no longer an explosion element. It has been replaced by radiation as the new element. Radiated enemies explode when killed, and damage nearby enemies.
However, there are some weapons that deal splash damage, similar to a rocket launcher. These weapons are usually made by Torgue.
It’s different, but it still works. I found a gun that was made by Torgue, but was basically a magnum style pistol that shot mini-flame rockets. Got to use that sucker for like, 12 levels it was so badass. All the area of effect damage of a Torgue weapon, with all the elemental effectiveness of a Maliwan, with all the kick of a Jackobs.