Same email on two accounts could well be a flag. Same password as well? I should hope not!
Of course husbands and wife will usually share a surname and address so that aspect shouldn’t be an issue.
It’s not good account hygiene with the same organisation to do that sort of thing Not wanting marketing emails is a poor excuse given you can opt out. I’ve never had a marketing email from AA because I opted out from them so the only ones I get are related to flights.