Unless there is a paranoia that the devs will require 3 maxed pets in the future, you would only need to just own a 3rd pet. You would simply just max out Manticub and the faction pet Cactnid Kid to fulfill the 2 pets at level 20 requirement.
There’s no hard rule that Talon is a 2nd pet for Leonis Empire. In fact, we could just as easily get Alex before Talon and Talon could be stuck in purgatory for another year. No one would really care for Talon at that point since we just need any pet for Leonis Empire.
Talon is also a cosmetic pet, so they really could just release it at any time because they feel like it. Cosmetic pets have been mostly associated with holidays, but it doesn’t mean they HAVE to release it at those points. Its just the easiest reason for them to release content.
There’s a lot of unreleased pets, but it doesn’t mean any of those pets have to be related to 5.0 at all.
Its their own desire to keep some kind of release schedule available for years on end that’s holding back the creative design process of the pet system. (Pet gnomes are the reason its held back in the practical sense).
When pets were originally proposed, they were going to do many wild and fantastical things bringing many of the unused functions to be more interesting. They even considered the idea of releasing multiple pets that do the same function as existing pets (if anyone remembers the Q&A when it was brought up how pointless the XP pet was)
Pets appear to be mechanical in nature, but they never had to be. There’s no hard rule each kingdom had to have 2 buff pets, its just easier to spread them out that way. If anything, if they ever get around to releasing duplicate effect pets, the 2 buff pet setup can easily be a thing of the past.