This is possible, depending on your setup you have two choices available to you:
1. Using a Pre Loader extension you can check for the class in question and then add an attribute to your data layer . And then use this in your load rule. This is VERY dependant on when your pages loads compared to when Tealium is loaded onto the page.
2. This is the recommended approach, using the newer uTag versions v4.26 and above, you have the ability to suppress the initial page view and then re-evaluate the load rules when the page has loaded. This is done with the use of the window.utag_cfg_ovrd object. Details can be found here if you search for ".load_rules_at_wait".
If you have any further questions please reach out to your Account Manager.