This doesn't really change anything for me. I must be a minority of people who would always always blow up the old gear i just made another better version of.

Dying an item would reset spirit bond i remember but the materia and +1 would remain. This may not apply since dying is going to change. Pretty sure it was said we will be able to dye dyed gear so something will likely be tweaked. If not, at worst, you'd have to be a crafter to loophole your way out of being stuck with sb'd multi-melds. This also wouldn't bother me at all.