I get what you're saying about it not being a loophole, although it has been described that way in the past.
The CBA rules have been clarified on the NCAA "loophole," but Anders Lee still could have become a free agent this summer if he really wanted to.
www.lighthousehockey.com
The last CBA was tightened to keep seniors from getting the double benefit of a college degree and becoming a free agent soon after leaving school. If that's the intent, it still seems like there's a true loophole that doesn't seem to be exploited.
If a player went to the USHL for a year and then college for 3 years, they could "leave" school to become a free agent. And then just return to school for their senior year to graduate and/or sign with any team whenever they wanted. Similar to what it seems like Weiss just did, except it would happen between the 3rd and 4th college seasons.
If that loophole exists, it makes me think there may be some gentleman's agreement amongst teams/agents/advisors/coaches to not exploit it. If players started doing this, it would disincentivize NHL teams from drafting kids that are heading to USHL before college (probably mostly mid/late round selections like Romaine) which would drive talent away from the NCAA route.