I mean, if we want to use WoW as the example, pet diversity was a complete waste of resources early in the game. The diversity only yielded returns as the pets increasingly became more or less just cosmetic choices, as prior to that there were a couple of correct choices and a lot of wrong choices with no clearly defined role to fill. FFXIV would likely be the same, unless they want to make an extremely convoluted system where every pet has a niche all to itself. Alternatively, if you just want more egi glamours, I'd expect to see more of those over time, but as they're just a unique cosmetic option other classes don't really have any equivalent for, I wouldn't expect them to be a high priority. Prioritizing content just for summoners would be unfair to everyone else.