I actually meant Scale Mail (thought chain and scale were swapped on the armor weight list cause I wrote the post off the top of my head.)I think he meant chain shirt.
The point is... a 1st level character who has Medium Armor Proficiency and starting gold (which includes the druid) could have a max AC of 16 from armor. 14 from the scale mail (highest AC Medium armor within the 100 gp starting limit) plus 2 points from DEX. So that is what a druid character theoretically should be able to have, except because of the "no metal armor" fluff rule, which means the best they can have is 12 from Hide plus 2 points from DEX for a total of AC 14. So the druid is 2 points behind the cleric in AC merely due to a fluff rule. Which is fine in of itself I suppose, but the game really should have given something back to the druid to get that starting AC of 16 to match the cleric... and they do, via the Barkskin spell. It's not a perfectly balanced match between the two classes (because the druid has to spend one of its spell slots on it) but it's certainly better than before.
But then things get even more unbalanced because that identical cleric and druid don't gain the same benefit from a shield and cover. The cleric gets those +2s (or +2 and +5) stacked onto his 16, the druid doesn't get that. Simply because WotC got cutesy with their write-up for the Barkskin spell for some odd and no discernable reason. Which is why I just ignore the Sage Advice. It's penalizing the druid (in my opinion too harshly) merely because they wrote the spell weirdly.