>>32967282I always imagined all recurring legendaries just happened to be set free for reasons by their respective original MC trainer, or were never truly "caught" by them.
I have trouble believing the lake trio, who supposedly created emotions and knowledge in mankind, has more members in their species than just the one unique trio, but in all fairness that's my own logic (and by extent, headcanon).
Lugia I can believe because there was a little Lugia and an egg in one of the movies I think, so I assumed in games it was limited to one for balance reasons, and I can only assume from that that Ho-Oh would be no different. Same applies for Lati@s.
It's just the more powerful legendaries that I can't suspend my disbelief for. For all I know the Johto beast in Kanto just happened to stroll there at the time, so it's not necessarily another one. For all I know the Hoenn trio was set free after the crysis was over.
It's all just a huge grey zone really. There are so many possibilities that talking about canons is pretty much impossible.