[edit: just to be clear, if a GM told me not to do something in game, I wouldn't do it. But until then, it's fair game IMHO]
"This will be fixed in a patch, please refrain from doing it." is not equal to "this is an immediate, banable offense, without any warning". And this is after you put in a ticket that specifically asked about this (I'm assuming, I didn't see the ticket)

Honestly, the CSR team is so busy with tickets that I doubt they are watching people running instances - ever, unless they get some specific report on someone and are somehow magically quick enough to catch them in action.

I think you could still use this technique every day until, (and if), they patch it and would not have problems. The worst thing they would do is warn you not to do it again. And I think the odds of that are slim and none, and slim's out of town.

There are still tons of bosses that have "exploitable" issues (Gorefiend being pulled through the door, ZA adds despawned (fixed now actually), avoid the storm on first boss in SV, as an example) and I've yet to see anyone get banned for using them. And you've had entire guilds use them for months with not so much as a warning.

The only time I've ever heard of problems is when a GM tells you specifically, don't do this anymore, it's not working as intended, and you continue to do it.

Multiboxers are probably going to be some of the first people to find new and creative ways to fight bosses.