Interesting idea, let's backtrack and review what the armoury system was supposed to be in concept.

Originally the game was soley about your character. You raised your character and it grew horizontally by earning skills spread across various weapons and tools. The goal being that if you leveled every skill available in the game you could cherry pick abilities to form whatever role you wished and play that role however you decided. It sounds interesting but also fundamentally flawed. To have motivation to "level all the things!" each skill category had to be extremely gray and not focused entirely on a role or design of it's own.
The problem was that many players didn't really connect with this and a lot felt bothered about being forced to level classes they weren't interested in. Most felt like their Frankenstein hotbar of actions available didn't really formulate the equivalent of a defined class role and certainly not close enough to what most identify with what a Final Fantasy game is.

So they took the drastic action of basically nullifying most of what the armoury system is. But now I feel a bit confused as to why even keep it this way at all? There's no clear understanding yet why to leave in the base classes and have they branch out into jobs? One for solo one for party is the main assumption but is that even necessary? Sounds complicated if you're a newcomer. My two gil is that it's to keep people from freaking out too much over the prospect of losing their "thaumaturge" or "gladiator" (whatever the hey that's supposed to be in a FF game) with the dual benefit of maintaining time sinks.

Personally I suppose I don't care, many MMO have class trees this is nothing new. Even XI did to some extent. My largest gripe about not completely revamping how the class system work, the sword of Damocles over all our heads, is the tie to class change still being based off a single weapon or tool equipped. It's so severely limiting to the game, and honestly very pointlessly so. The only benefit it's ever served was that you could change your class where ever when ever you wanted to but could this also not have been done through simple means of a menu?
The armoury system changes quietly have rid of the concept that your character learns sword skills by using a sword, and shield skills by practicing with one for a while and later the player pieces what is learned to attempt to perform a role similar to what a paladin may. Instead, now, you equip a sword and you are a paladin with your abilities already predetermined. So what is the point of still bottle necking the game that paladins and by extension gladiators can and forever will only use one sword type. Or that there will never be novelty equipment outside armour and for each new class will have to be even more development time and money spent making sure each class in game gets a reward weapon to use.
I just cannot fore see this being healthy for the game on the long term. And I cannot help but feel there are better ways job changes can be handled while they have the rare opportunity to drastically redesign with version 2.0.

Anyway, sorry to have highjacked your thread with my long ramblings and rantings.