Another day another misinterpretation of the design manifesto.
To be fair, 10+ years later it's easy to not know/remember the MMO landscape at the time of release. The pain points GW2 went to tackle:
1. A subscription fee combined with time wasting mechanics. Crafting in GW2 compared to Vanilla WoW? Having to constantly back track to "" turn in quests
2. The gear treadmill where it was designed to be extremely difficult to ever fully gear your character for optimal stats.
3. Combined with 2, a role system that made it either tough or expensive to change roles on the fly based on group needs.
4. Max level being a long term goal for new characters versus an experience of leveling how you choose and extremely fast
As others have said, they never said there would be no grind. Just that it wouldn't impact power, max stat gear, roles can be interchangeable, there's not one class that has to heal because others can't, and max level is easy to obtain. With that in mind, Halloween doesn't break anything here. It falls right in line