>bdsp gives you a free mew if you have let's go save data and a free jirachi is you have swsh save data
>legends arceus gives you manaphy, phione, darkrai, shaymin, and arceus without needing to get an item from a wi-fi event
I think Mythicals are definitely being looked at differently by Game Freak at least. I wouldn't be surprised if SV give you free Mythicals again for your save data. I think the number of Mythicals ballooned to a point where it became a pain in the ass to do events for new ones and redistribute old ones, which is why the in game events for them stopped and they just became box filler that don't matter. So now they just hand them out like crazy.