Battle.net and Xbox accounts (on PC only)

me and my girlfriend play Diablo 3 and currently she lives in Argentina and I in the U.S., I wanted to surprise her with gamepass but the only way I could surprise her due to the region differences was buying Xbox gamepass on a secondary xbox account I had, as buying xbox game pass as a gift wouldn't have worked cross borders.

Well now we have made a lot of progress together in the game but our gamepass has expired, and we are looking at purchasing the game, but I want her to own it completely and not be in my name, I can see a way to change the email of the battle . net account and the name and details to match hers and give that all to her, but the unlinking of my xbox profile from the battle . net i read an article here: https://us.battle.net/support/en/article/14014

Disclaimer*: Disconnecting the connection will result in the loss of all current Game Progress and any earned or claimed rewards. These cannot be moved to a new Account.*

but it doesn't clarify WHERE the progress is lost, I would think that battle . net is where the progress would remain even if it is unlinked from the xbox profile as that is where the purchase for Diablo 3 would be, but I can't find clarification on this. We do not care about the xbox achievements being lost on that profile, and I want the battle . net account to be linked to her xbox profile.

Any clarification on if I unlink the account from my xbox profile and link it to hers is there an issue?

I wrote support but I don't know how long they will get back to me nor if their answer will be sufficient.

If anyone has any experience with this situation please provide any input (: thank you!

sidenote: (please no lectures about long distance, we do see each other periodically in person and have plans to make it permanent, but that is not what this is about)