When you opt out, your credit reports and personal information are not given away for marketing purposes, pre approval purposes, etc etc..
When you apply for a mortgage and you havent opted out, generally you can receive all types of offers in the mail and on the phone if your number is listed on reports. The CRA's then generate and sell list to creditors, insurance companies, brokers, etc etc...
Junk CA's receive the information and check it against their database, and since you just applied for a mortgage, know your information is correct and updated. Since junk CA's (all CA's in my opinion) have a bad reputation most of the time, you just never know what tactics they will try to get you to pay them.
the can soft you and see your inqs and can see if you have apped for a mortgage, which will make you more inclined to pay
So opting out does not effect legitamate creditors who you designate to pull your report or block them?
No it does not, it's not a freeze, it's just like being on a do not call list but for credit cards etc.