Risks associated with linking Amazon Prime and Epic Games accounts (I know, I know...)

I'm mightily tempted, finally, by this month's Prime subscription's giveaway of the game KeyWe, which requires Epic Games account-linking.

I'm not really sure of what data risk to expect should I finally expose my real Amazon account to Epic Games (which is pretty much a dummy account that I've only been using to collect their giveaways ever since they began). I have refused to link accounts all these months so far. What do you think?