I just posted this on another topic but basically maybe the explanations are just trolling us to the real concept behind the Con/Thm line.

If you take a look at the THM ice spells, only THM can use them. What spell did BLM have that only BLM could use(excluding elementals spirits), Freeze. If you take that into consideration it's quite possible that these 5 spells types are just effects based on the arm you are using

So with Conjurer we have
-DoT, AOE dispel
-x element eva down, aga with chance at enfeeble
With THM we appear to have
-Ancient Magic, Freeze
-aga magic Firaga I-III
-single target Thunder I-IV
Then for BLM we appear to have
-Freeze 2

Overall til more data is seen there's no telling if they have actually eliminated water or not, they could actually surprise us and have the element be based on the trait you have equipped. So CON could have the traits of Water/Wind/Earth element and THM could have Ice/Fre/Thunder and when you have said trait active your spells will follow those line of elemental potency. With 12 possible traits for each job it could be possible though I already know that the main problem that could debunk that concept is the fact that you can't use traits on other classes which would kill the BLM ability to use those 3 elements. Though they already can't use 1/3 of those elements as far as we know.

Would be nice if there was less speculiation over this though I am curious to see if they actually comment on the lack of Water magic. It'll definitely be interesting to see how next week progresses if they decide to release an updated ability list or even explain why they made the choices they made lol.