
I grok do u |
Not seeing Primordial as a language in Pathfinder; the elemental planes each have their own language (Auran, Aquan, Ignan, and Terran - although recently renamed in PF2 remaster). Although the rules make clear that there will be no exhaustive list of languages, so GMs are always free to add or change languages as desired.
First world speech acts as a base root for Aklo and Sylvan, so that speakers of those languages have a rough understanding of what is being said. Absolutely reasonable to add Primordial as a language that can be roughly understood by speakers of the other elemental languages.
Wiki links:
Great Beyond languages

Azothath |
I believe the OGL PF1 used only covers things in some 3.0/3.5 products. Anything else Paizo would have to specifically avoid.
The description of utopian, protean, truespeech is interesting. I'd think incorporeal non-verbal languages were earlier than the listed ones... math is actually a language about imaginary concepts, symbols, and procedures.