Extremly flexible would be to allow me to rebuild my chars as they were, giving me back my coins plus a little extra is not even close to that.
If you rly want to limit access how about not giving smourne to anyone and keep it only as a drop at LK in ICC 25HC, pretty easy.
And if you want a clean restart why do you keep track of who bought smourne and who didn't? Doesn't make sense at all sorry. You will have to come up with something better than "We don't care what happened before wipe but only the ones that had smourne will get it now".