You can check
this instead on the Blue Mage.
Then you can put all the pieces together with what is being said about BLU, including small ones like
this.
The way things are worded, save for a couple things, are all left in ambuiguity. This just lends credence to the fact that this particular job is going to be left to collect dust as much as possible, that it's worth null. An entire class treated in this manner, what Zsplash was essentially saying.
Unless things change completely the ONLY guarantee is that BLU will be 60 during Shadowbringers, given all the info, and it's still worded as "can expect". Considering they released the 1-50 experience, instead of any other choice, then it is not a wild assumption at all that it's likely the thing people will see, will be the 10 lvl addition.
When such language is used like "doesn't have to" in this instance, it doesn't mean anything. They're trying really hard to keep everything vague just in case, but what it does in the end is just make other things clear, much like what all the other justifications brought forth reveal other things.
It's as if you were tasked to construct a rocket to send another satellite into space, but because you think that this satellite can't go up there (even though it's like all the others) and then tamper with the satellite to malfunction just so you can claim "See I was right!" when it was entirely possible for that to work as it should have.
5.x means the entire expansion, and if treating these jobs/classes that are already established and have fanbases as if they were expendable is to be "expected", then we are all doing a good job indeed.