How is changing the trans fluid at 15K maintenance???
Changing the trans fluid at its prescribed intervals is maintenance.
Changing fluids is maintenance, regardless of the interval used. It's up to the owner when s/he wants to change them... whether it's following the maintenance minder or not.
The same goes with changing spark plugs, engine oil, coolant, cabin/engine filter, rotating tires, etc. These items all fall under maintenance.
Did the OP have to change the trans fluid? No. But if the OP wanted to, it's out of your own pocket... unless the dealer's nice enough to goodwill the service. It could've been something the OP could have asked for.
Many 7th gen owners (especially V6 auto owners) and some 8th gen owners change the trans fluid a lot sooner than what the manual has listed. Some do it every oil change, some do it every other oil change, some do it every 15K or 20K miles. Why? As preventative maintenance
against trans failure.
7th gen V6 auto Accords (particularly the 03-05 years) were notorious for trans failures. The same goes for the 6th gen V6 Accord, 2nd gen Acura TL's and CL's, 3rd gen Acura TL's, 1st gen Acura MDX, 2nd gen Honda Odyssey's,..... I wouldn't be surprised if the 9th gen CVT was added to that list.
Since we choose to change it sooner, does that mean we should expect Honda to cover it under warranty?