Even now when I do a search in metacpan for Net::MyIP, it doesn't return anything.
For me, https://metacpan.org/search?q=Net%3A%3AMyIP returns 2 results, the second of which is Acme::CPANModules::NewDistributions::202001 which does actually contain a reference to the original Net::MyIP (this is the first time I think I have ever found the Acme::CPANModules::NewDistributions::* namespace useful). So, it's well hidden but the reference is there. I do think it would be good if MetaCPAN's search would return BackPAN results for modules which are an exact match for the search term (and clearly mark them as BackPAN), but it doesn't.
It would also be useful if the email from PAUSE indicated that it was an unauthorized release but I don't know if it does that?