I used my old Apple ID to download Pokémon GO and connected it with my Google Account.
If I delete the Pokémon GO app and download it using my new Apple ID, but sign-in with the same Google Account, will I lose my progress and Pokémon?
I used my old Apple ID to download Pokémon GO and connected it with my Google Account.
If I delete the Pokémon GO app and download it using my new Apple ID, but sign-in with the same Google Account, will I lose my progress and Pokémon?
You should be fine, I've used the same account (gmail) on 2 different android phones and an iPhone and was able to switch without issue.
Since you login with your Google Account or Pokemon Trainer Club account and not your Apple ID, you should be find switching between devices.
I have an iPhone 6 Plus. You will lose everything. The trainer login is corrupted. It does not store your login information correctly from the start and leaves you with attempts to login before locking you out from access to the account you initially set up. Therefore, you get forced to go through Google, which works fine at first. However, if you sign out of your app, delete it, and reinstall it, that login is corrupt too. He app will recognize your login email address and password, but the ap itself doesn't have a prompt to sign into an existing account. Basically, it starts you over from the beginning as of you initially downloaded the app for the first time. You cannot even reach settings until you've collected the first Pokemon and created another nickname. Aka, now you have a trainer login account you cannot access, which is still there because the nickname you chose for it is unavailable, a Google login account with one nickname and all of your stuff that you cannot access, but it is also still there because again nickname you chose is unavailable, and a 2nd Google login starting to the newly downloaded app, which uses your same Google login information, but starts you over from the beginning. Plus when you send requests to support for troubleshooting or account access information, nobody responds. You're supposed to get an email within 24-48 hrs and nothing...
Short Answer: No
Pokemon Go's data is stored on their servers. So, your phone doesn't really "save" anything. It contains a cache of your current progress (which constantly syncs with the servers) and your system settings, but all of your Pokemons, items, badges... all the goodies are stored at Ninantec. So, if you sign in on a different device, all of your stuff should pick up exactly where you left off.
I started playing on my Nexus 5 through my Gmail account. When I got my Samsung S7, I just logged in and never skipped a beat!