So it would be best if those services simply advertise their new address on the v2 domain right? Rather than sit still and lose their traffic when everyone's forced to, or when attacks really become feasible.
It's not even a hard upgrade, afaik it's literally just a change of what address users have to copy/bookmark and nothing else. I just don't get what the reason to not upgrade is.
Sure, but that's not effort on the site's behalf so they can switch over and make the V2 show the redirect notice. If IPv6 would have been this simple, just show a redirect, we'd have upgraded long ago...
It's not even a hard upgrade, afaik it's literally just a change of what address users have to copy/bookmark and nothing else. I just don't get what the reason to not upgrade is.