In the US, it is an Individual Donor Assessment and applies to everyone. Everyone gets the same question tree, regardless of sexual orientation. If you have had a new partner in the last 3 months or have multiple partners that doesn't defer you, it sends you to the next tier of question: have you engaged in anal sex. Yes to anal with a new partner or multiple partners is the deferral. If you haven't had a new partner or multiple partners in the last 3 months, you will not be asked about anal sex. Canada went live with their individual donor assessment a year before the US and has noted a slight drop in donations in straight donors because they are now being deferred for high risk activity when they were previously missed.
Prep is listed under a medication deferral. First responders that take prep for protection from workplace exposure are deferred as well.