I’m not sure what you’re thinking, but thousands of magazines were handed in, registered or moved out of state.
CT complied quite nicely, actually.
Complying with such laws would not be something to brag about. And I doubt most actually complied, unless CT has a deep apparatus in place.
Only a very small number of people registered their AR-15s - it's estimated maybe 5 - 10%, (they know about how many were sold in the state - a hell of a lot more than were "accounted for").
I think we could draw the same inference about magazines. Most people just don't talk about it anymore. For good reason.
I can guarantee you that hundreds of thousands of others weren't.