Apple Watch Fitness Data between Apple IDs

Hi, I am trading in my iPhone 12 on iOS 18 today and I have erased/removed it from Find My, after backing it up in iCloud. I also unpaired my Apple Watch Series 8. My parents are doing the trade in for me since it’s the only day we could do it. Since I have work today and couldn’t come with them, I paired my watch to my work phone for now so that I could still make sure I close all my rings today. My question is, when I get home later and want to switch my Apple Watch back to my new personal iPhone, will today’s fitness data transfer with it, or is the fitness data stored on each phone? Is there a way to transfer that data manually at all? Thanks in advance!

Edit: As referenced in the title, my work phone and personal phone have 2 separate Apple IDs which is why I imagine the data I’m wanting wouldn’t be able to just be restored from a backup