This play isn't an exploit any more. Now the QB waits for the TE regardless of whether the back is coming out of the backfield wide-open. The one time I did see a pass to that back, the one that used to be "auto TD", a defensive player practically teleported to his location to make the tackle as soon as he caught the ball. I mean he must've jumped five yards laterally from one second to another. So, yeah, this play is nothing special any more.

You're correct. It took code iterations for it to be adjusted and it went through some changes of diminished effectiveness but it definitely has been handled now for the time being. Things change on MFN constantly, though, so you never know when it'll open back up.