Guild wars 2 also minimized how many abilities each class has in comparison to GW1 which had tons and tons of abilities.

HOWEVER, not only are there still more abilities to learn than just 15, but each class is able to equip more than 1 type of weapon with each weapon giving a different set of abilities to equip.
you can also change your weapon by just a push of a button at any given time allowing you to change which abilities to use according to your current situation.

this new 15 ability thing SE is doing might not bode over well in the long run.