[Inquiry] Please provide clarification on "Link a Device"

I wish I had read a bit more on this and use my tiny brain as well... I actually wanted to try linking my old android account to my second iOS device, which I did, to later on realize how s t u p i d I was, as it did not link the android device to my second iOS device but rather overwritten my Game Center account all across all my iOS devices, meaning I lost my account.
Don’t be as ignorant as me, because there is no way to reverse this!
So be careful with this new feature.....

Br,
A dumb player