I don't really see the point, a small amount of armor isn't going to stop me picking an S tier hero over average ones. So what if hooktusk and jandice have 40 health and zephyrs has 5 armor? It's not gonna stop anyone picking the top tiers because that 5 armor isn't gonna be what gives them an insane lategame.
The biggest winner out of all of this is definitely AFKay though, starting the game with 50 health is huge.
Might help your late game if it allows you to tavern more quickly early on and find those powerful T5/T6 scalers, though. Either way, better than nothing. Impossible to balance asymmetry like this on hero power alone, so this is a good change.
It's another interesting system that can be taken advantage of when the armor rating doesn't match your skill with a hero. Also buys a little time for those heros that have delayed advantages to reach their inflection points.
I actually did not think the change was going to be good at first. I thought it would just encourage certain heroes to just power level and it would become just a race to high tavern tier. It doesn't seem to be the case and I like that I can get a little bit more time with certain heroes to get something going. I think the way they rank heroes needs some work, but overall pretty happy with it. It also seems like it makes murlocs in general more viable.
Now of they could stop pushing unfun heroes like Diablo and Sneed I'd be extremely happy.