Regardless of what an individual employee told your brother, Apple did provide battery replacement at that time. That’s why they dropped the price down to $29 when the tech media hyped the throttling angle. People also complained that Apple wouldn’t replace their battery if it was above 80% capacity due to supply constraints.
Yes they corrected the situation after the fact, but at first, an end-user had no way to know that their battery was below 80% health and needed to be replaced, other than symptoms.
That is the problem. Again, no communication; customers left in the dark and thinking that they needed a new phone because Apple couldn't be bothered to let the end-user see a health number, and couldn't be bothered to tell them that their device might slow down due to battery age.
Now they are paying for it, and rightfully so.