The new Reddit design has the platform stripping HTTP referrer (referer) data from outbound links on the website. This includes ads. I asked the Reddit Ads staff about this and they informed me that this was added intentionally.
The “noreferrer” HTML attribute strips away the referral data from one website to the next. This means that a website can look at their server data and know how many website visitors came to their website on a particular day from another website and look for patterns to help those users have a better experience.
There doesn’t appear to be any security or privacy reasons for this change and it only appears on ads using the new Reddit design. On the old design the links send referrer data normally.
If you’re an advertiser this means that you’re likely seeing an ever larger discrepancy between your Reddit Ads reported data and the data in your analytics tracking. The only way to track Reddit Ads data now is to use UTM parameters. If you’re an agency your clients should be noticing a drop in Reddit traffic from both organic and paid due to this change. There is currently no way to improve the tracking of organic Reddit traffic.
For those using the “old” Reddit design you can replicate this by going to Reddit.com using Chrome’s incognito tab, navigating to any advertisement (or any organic post), right clicking on the link included in the ad/post and selecting ‘inspect element’.