Well increasing minion hp is already on the table although the bar is at lvl 35 not at 20. I dont think Lts and Bosses will be kicked up.
I dont think enhancements will take a nerf. More likely is that they will nerf inspirations.
I dont think they will hit defenses beyond the invuln line.
I dont think they will hit Hasten. Last time they tried to hit it the playerbase practically threatened them.
I think you will see an increase to Lt and Boss xp relative to minion xp.
I think that mobs at all levels will be given more powerful abilities to use in combat. This is how they will stealth nerf soloing.