I'm fully convinced it would have come out this year but got delayed to next year due to the next gen console delay. If the rumors are true, then Nintendo was planning Switch 2 for this year at some point, and I'm confident GF would have released this game when the console launched, but since the console got delayed it has forced GF to delay, which is why for the first time since 2015 we won't have a major new Pokemon game or expansion  this year.

I don't think this is GF willingly trying to polish the game more. I think it's all about next gen launch.

Regardless, if more time to polish up the next generation of Pokemon and the next Nintendo system before releasing them, then I'm all for it.

So so would Pokémon Legends Z-A be the launch title for the successor? And is it still? How many 1st party launch titles will the successor have?

Hopefully a lot. One each for Donkey Kong, F-Zero, Metroid, Pokemon and Wario. At least that's what I would prefer.

Nintendo has on numerous occasions delayed launching games that were gold to spread them out. If they have too many games ready by launch, they will delay one or more to fill other parts.

Plus, this gen is going to be the next big leap (last one was Wii U over Wii) so their teams probably will need more time to adjust. 

Nintendo has on numerous occasions delayed launching games that were gold to spread them out. If they have too many games ready by launch, they will delay one or more to fill other parts.

Plus, this gen is going to be the next big leap (last one was Wii U over Wii) so their teams probably will need more time to adjust. 

Big leaps hardware-wise?

If they only release it on Switch 1, only on Switch 2, or cross gen: "That's what we meant the whole time!"