I'm more arguing that because you see theoretical gaps that the developer team does not really. So far your argument for it is.. really weak. Red Mage barely uses Earth, and uses less Wind spells than White Mage did in Stormblood. There isn't any indicator that they were trying to give a "techy" job to Tanks either. After all I can easily point at the VIII theme that Shadowbringers has (even if it's mostly just Eden) and argue that as a possible inspiration. Or any number of other possible answers.

Long story short, these "gaps" you're seeing aren't really ones they probably see. If they are they clearly aren't in any rush to fill them. And unless you're able to actually provide evidence that the team is concerned about giving tech jobs or elementally themed jobs or whatever then it seems unlikely to be an important matter. Especially when you consider all jobs use aether so specific elemental representation probably isn't on the forefront of their concerns.