The wizard was sometimes a little underwhelming at the start of the campaign, so these give him a bit more to do. Once you’re part way through the series of adventures he quickly gets more to think about than the other Heroes, so you’ve got to be careful about where he starts. Complex at the start makes him an impossible tangle at the end – especially if you’ve got one player looking after all 4 Heroes. This variability in play options is one of the challenges here – how to be sufficiently interesting when you only have one of the Heroes, but not overwhelming when you have all 4.
Anyway, the changes:
Firstly, if the Wizard is not in an enemy front arc he can use an action to create a new power 1 energy crystal. This is a toned-down version of what he can do in the Downtime section of the Adventurer’s Companion. Power crystals are always useful, so filling an otherwise quiet moment is a helpful option.
Secondly, the Flamebolt spell is now long range. It’s not the most powerful spell (though it’s better against Goblins and other stuff that’s easier to kill than zombies), and that’s exactly how it should be. It’s petty magic and can therefore be used every turn. It can, however, be boosted with power crystals, so every now and again it can be quite pokey. It’s intended as a backup, not the main magical event. Still, bumping it to long range makes it a little more useful without making it overpowered.
Lastly, the wizard gets an extra power 2 energy crystal in each of the Core adventures.
Added up, I think this nudges the wizard to where he needs to be at the start of the campaign, without causing lots of problems later.