Less content in the Stormblood when compared to Heavensward?

[Bourne_Endeavor]

Fair enough, the dev team said that.
If I want to nitpick a little, I'd say that the burden is not the same when you design three new jobs while releasing an additionnal job than when you just do three new jobs.

But, hey, we'll see in February.

You have to also consider they still haven't figured out how to balance those jobs. Astro went from borderline worthless (3.0), to underplayed (3.1 onward) to competing with Warrior for OP status (3.4). It took them three patch cycles to finally get Machinist settled. None of this factors how the other jobs are influenced. White Mage basically has no purpose and the continual buffs to Machinist forced attention onto Bard, wherein both pushed Black Mage and Summoner out. Meanwhile, Dark Knight has been kicking Paladin since 3.0 and Monk struggles to find a place in the meta. I'd rather they focus on adjusting the current jobs instead of adding new jobs to further complicate things.

[Reynhart]

You have to also consider they still haven't figured out how to balance those jobs.

That's totally different topic
Can they add three new jobs ? I'm fairly confident they can.
Should they add three new jobs ? Well...for DPS, I think they were able to maintain pretty much any setup equally viable, since you always have a lot of DPS in a party. For tanks and healers, as long as we have more jobs that available spots in a party,some of them will always be kicked away.