Well it's official now! FFXV crossover event on the way!

[Beckett]

Did you even watch the video? I'ts obviously tied to some trial with garuda.

Rathalos mount is tied to a trial too, doesn't mean there's not grinding involved. The difference is that content will be available as long as the servers are live, and the FFXV event is likely for a limited time only.

If Regalia is an easy unlock, I'll eat my hat, but I seriously doubt they wouldn't make the very first 4-person mount very difficult to obtain.

Edit: Thinking about it again, it's highly likely that the FFXV event will be permanent, like GARO and Monster Hunter are.