Would really love if #2 could happens, but I'm afraid the design was intentional so that each player save data on server side would only store those player actually uses rather than saving all available pet options., hence not only becoming storage issues, but also (probably mainly) memory usages. I mean... we do often had auto-translate rotations on maintenance pretty often to nix out verbs SE deems not worth to keep longer, probably for similar reasons. The other viable options would be taking similar path with FF14 does: trim the list of available pets, I mean... let's face it: more than 90% on the list won't be used anyways & kinda redundant. Maybe do something like SMN.

TLDR: PS2 engine limitations. lel