Essentially, hyperlink auditing (<a ping> attribute) is designed to notify an arbitrary website when you click on a link.

Apart from the fact that its sole purpose is to notify trackers when you visit a link, Safari does not allow uBlock Origin to intercept these requests. In other words, your filter lists will not work against these requests.

As per a hidden WebKit setting, run this in your terminal:

defaults write com.apple.Safari com.apple.Safari.ContentPageGroupIdentifier.WebKit2HyperlinkAuditingEnabled -bool false

and restart Safari.

Same as above, except replace com.apple.Safari with com.apple.SafariTechnologyPreview:

defaults write com.apple.SafariTechnologyPreview com.apple.Safari.ContentPageGroupIdentifier.WebKit2HyperlinkAuditingEnabled -bool false

and restart Safari Technology Preview.

Check out gorhill's wiki for more information.

To re-enable, replace false with true above or delete the key:

defaults delete com.apple.Safari com.apple.Safari.ContentPageGroupIdentifier.WebKit2HyperlinkAuditingEnabled