The problem is, it's not being offered as a prediction from the poster I was quoting.
"I think next expansion is when they'll run out of new jobs to add," or "They had a hard time balancing healers which is why they didn't add one and I think that could be true for all roles now," is one thing. Except even if that were true, it would be up for a debate; the addition of Gunbreaker, for instance, led to a new analysis of the Tank role as a whole, which ended up reworking each to give them Main- and Off-tanking potential, AND a rework to Machinist to separate their mechanics, in addition to the new job.
Not at the cost of it, not in spite of it, but specifically because of the addition!
The way Malmstrom presented their "prediction", however, was equivalent to saying "Stop having fun, guys -- shut up about adding new jobs and focus on my main job," as if there isn't literally an entire subforum dedicated to exactly those grievances. Claiming after the fact that it was a "prediction" as valid as any was backpedaling.
You're right, eventually they will stop adding jobs. The keyword is "eventually", not "imminently"; Yoshi also stated that one of the guiding philosophies behind the jobs chosen for this expansion was evening out the number of jobs available in each role, which there is still ample room to do. Those people "waiting 2+ years for positive change" to the power balance, must have their opinions weighed against people who have waited equally long for new role options, if not longer for specific jobs -- I know people who are still hanging on to the many hints for Geomancer -- and as I said, reworks can come mid-expansion, as they recently did for Ninja, unlike new full jobs which the devs swore off doing in a regular patch cycle back in ARR.
Because you're right, players shouldn't have to wait that long for a rework to their job. There is nothing stopping them from dropping a Monk rework in the next couple major updates, but that's not something to bring up in a thread like this.
Someone sounds bitter. Not a good look, hon.