Problem SE have to consider is they aren't going to want to exclude low rank gatherers from the content, as much as I'd like to see it made rare by being grade 6 only. More likely it should go into grade 4 and above. They could balance current areas to fit it in but I'd much rather they use the opportunity to add new areas. It just makes sense to be able to mine in a mine. Who's idea was it to put grade 4 in Nophica instead of Nanawa anyway?

I don't think deaspected crystals will be used as the catalyst since battle classes can get them too. Though it would be interesting if you needed one of these crystals plus a catalyst to create the materia.