A few thoughts on Primals.

[FJerome]

This means there are few more options for primals in the future.
Diabolos as the primal for Tonberries? But we lack the traditional Light and Dark elements in FFXIV.

But we also have fewer elements in FFXIV, namely Fire (Ifrit), Ice(Shiva), Wind(Garuda), Water(Leviathan), Lightning(Ramuh), Earth(Titan).

Each element comes in umbral and astral-aspected flavours (for example, within The Twelve Halone is associated with astral-aspected ice and Menphina with umbral-aspected ice) so that opens things up a bit.

. . . Also, not entirely sure if Tonberries would count as a beast tribe, given the info you get about them in the Scholar quest-line.

[Kazamoto]

. . . Also, not entirely sure if Tonberries would count as a beast tribe, given the info you get about them in the Scholar quest-line.

A good point on that one, I had not done the Scholar quests so i googled some spoilers on it. Editing OP.