FWIW - I'm in the UK so things may be different, but...
I took my 2015 15" MBP into my local Apple store yesterday to have them ascertain whether it had a swollen battery. The Genius Bar tech confirmed it had and instantly offered to replace the top case and battery free of charge (normal cost quoted as £332.50 GBP), and stated that Apple replace swollen batteries for free within 3 years after purchase.
I didn't have AppleCare and purchased it from a department store (the store sold it with a free 3 year warranty, hence I wanted Apple to confirm if a repair was necessary before I took it back hoping for a warranty repair). The warranty expires in two weeks.
A month earlier I asked a non-Genius employee at the same Apple store about Apple's policy on replacing swollen batteries and was advised that they would absolutely charge for the replacement and my best bet would be to tackle the store I bought it from and see if they would cover it under their warranty.
So assuming all goes well, I'm happy. I get a free replacement without having to possibly battle the department store customer service. Also the repair should take a week and not 2-3 weeks that the department store quoted (this 13" 2010 MBP I've resurrected from the dead is nowhere near as nice).
Same here.. you get different answers from different people.
I just picked up mine after topcase/battery replacement and it was free of charge.