No, you and Trei are right, it won't be near the gear grind that WoW is and I do understand that.
But to me, one of the things is, when I was doing raiding on WoW and not playing GW for weeks, sometimes months, at a time, I never felt like GW had left me behind. This has something Anet says they want people to feel in GW2 as well. Well, if they had level cap increases in Factions or Nightfall or Eye of the North, I would have felt left behind.
It always felt good knowing I could put on my fissure armor, or some other armor from a different campaign and area and it was no better or worse than from anywhere else.
Well, if life makes me need to take a break from GW2 for a few months then, if a new expansion comes out, I will feel a need to "catch up" and that was how I felt in WoW every time an expansion hit. It's not what I wanted with GW2.
Hopefully Anet will respond to my question that they have decided not to do it, but who knows at this point.
If its not for you, its not for you, but i think you were operating on a false assumption when you believed they would never raise the cap. They never said they wouldnt raise the cap, in fact early in development, they were thinking about having no cap at all, and using area limits, and diminishing returns on being high level (not sure how they fully planned this, because it was early talk, and never came to fruition)
Anyhow, If your problem is them breaking trust, i dont think you can say they ever said they wouldnt raise the cap. If its about a gear treadmill, it really isnt a gear treadmill, its just how they can expand the game. Based on their current game design, they essentially have to expand the cap, whereas GW1 used story gating and skill hunting to set up progression post 20, this game doesnt have that. The skills are available from menus, you dont have to find skill trainers deep in the end of a story zone, you dont have to hunt monsters that only people in the final chapter have access to for elites. Basically this games progression is built more around experience, and the only way they can really expand content, and still offer progression with thier current system style is by increasing experience caps.
As far as gear getting outdated, theoretically, they could decide to make stats cap on gear at 80, but i doubt they will, so most likely gear stats will get outdated, however, gear is usually not a strong issue in GW as far as obtaining max stats, And appearance is level irrelevant, Keep in mind some of the most challenging armor to get in the game will be at level 35 55 etc, they fully intend people to transmute their ascalonian tomb gear to max level gear if they like that look, thats part of the core design of the game.