It won't happen, because that is the complete opposite of what the Armoury System is about. This is not FFXI where a Job and it's weapon are separate (and you had the whole problem of having multiple Jobs with varying proficiency in certain weapon types and having to learn skill points just to be able to use it effectively), here your weapon is your class/Job (hence why the term 'class' is something of a misnomer, and why they are more accurately and officially known as 'Disciplines' - it's a set of abilities based around proficiency in that weapon or tool.
Thus each class only has one weapon type associated with it (even shields fit into this as they were actually their own separate sub-class originally in FFXIV 1.0 called 'Sentinel' or SEN for short - which was scrapped when the battle system was redesigned around patch 1.20 in 1.0 and it's abilities given to GLA), and accordingly, you will not see each class/Job getting multiple weapon types to equip I'm afraid. Any new weapons added to the game will become new classes/Jobs, that's how it's been since the beginning and that is how it will always be.