A few things I want to take a look at with your situation:I have had my save file deleted from installing the update that i had downloaded on Saturday and i don't even think it would be from my micro SD card since it was a nintendo branded one (the 200 something GB one). Im so upset that i had updated it and purchased the DLC in the same timeframe from when i booted up the game after it downloaded the 1.2.0 update and then purchased the DLC before i had went to bed and got on just today after a couple days of work and found my save data deleted and had to restart my whole game from scratch when i had a shiny fuecoco that was evolved into a skeledirge. Man I've basically spent 175 plus hours on the game just to have it deleted.....seriously thinking game freak should at least try helping out the players who have had that problem happen. Its so frustrating to have however many hours invested and then just boot up the game and then witness that you have to redo everything you've accomplished in the game all because of an update patch issue.......im seriously regretting getting this game if i knew this was gonna be this bad just from downloading an update or hooking my account up to Pokémon Go or whatever originally caused this to happen. Im so fed up like its gut wrenching to have all my progress lost when i was so close to slowly getting every little item in the game with the help of a Paldea companion app i use to find out what Pokémon I'm missing or what kind of item i still needed to find.
1. Which error message did you get? Did you get the one saying "corrupted data was found", or did you get the one from the game itself saying your save data could not be recovered?
2. Have you pre-ordered the DLC via digital distribution yet or not, and if so, before or after downloading Version 1.2.0?
This line right here is what confuses me the most: "Im so upset that i had updated it and purchased the DLC in the same timeframe from when i booted up the game after it downloaded the 1.2.0 update and then purchased the DLC". Maybe I'm just mis-reading your message, but the way you worded this made it sound like you either A. downloaded the same update twice, or B. purchased the DLC on two separate occasions, once before the update and once after it.