Overmelding (and materia in general) has been getting updates as the game ages so its disingenuous to think it won't continue to do so.

Once upon a time a failed overmeld detroyed the item and the materia. Then, it became only the materia was lost.
Once upon a time, materia was obtainable only from spiritbonding and you didn't extract materia from the item, you turned the item into materia, losing the item in the process.
Once upon a time there were elemental and primary stat materia. There was also everyone's favorite "Accuracy" materia.
Once upon a time you had to meld each materia individually. Not "until you succeed or run out".

While I don't think overmelding is going to be removed (at least not anytime soon), I see it continue to get updates and QoL changes as the game continues to age. Biggest thing I'd like to see is an overhaul to the currently available materia. I don't bother overmelding DoH/L so I don't know if this is true for them, but anything beyond the two most recent materia releases for the expansion serves virtually no purpose in the game. A change to make all materia worthwhile at all stages of the game would be good to me, such as making certain materia only usable in certain slot numbers.