Spoilers for level 80 Scholar quest:
The final Scholar quest basically wraps up the entire Scholar questline with the curing of the tonberry plague and all the nymians being turned back into their lalafel selves, so there isn't much more to do there with the whole tonberries/nymians storyline.
That being said, tonberries are woefully under represented in FFXIV due to their SCH lore connections. But since the Nymian tonberries were just mutations based on the actual voidsent tonberries, there is always the possibility of seeing "true" tonberries as voidsent. They may not look like the cutesy traditional-looking Nymian ones, and perhaps will look more like the monstrous FFXI ones instead. Either way more tonberries please!