Worldbuilding

Oh man, I typed a big response and lost it so this is going to be much shorter whoops.

To answer your questions: In the time immediately after the conflict there was a lot of desire to "go back to elf", but there were a few problems.

• They went through brainwashing to feel separate from elves (as they were created to kill them) and even though they managed to kind of break out of it, they still feel like they are and are not the same at the same time. They don't really "fit" anymore.
• It wasn't actually possible to undo the changes.
• Elven society made a decision to cut them and similar races off completely.

As for culture, there are virtually no similarities remaining at the main time period I'm writting in, as elven culture further developed in a magic-centric way and goblin culture developed in a very different direction. And since they weren't interacting whatsoever during that development, very different.

Of the elf-based races, goblins are probably the most content with their new way of life, and are usually the least ambitious. While others, like humans, deeply desire reclaiming magic somehow (not being an elf again, just getting their "birthright" magic back). Goblins have a bit of pride in their new lifestyle, and power like that would disrupt their way of living. They don't really teach about their origin (though they retain stories of it as needed) and they live among many also non-magic races, so there isn't a lot to be jealous of (for the time being).

There's also definitely some difference between the ones that have a symbiotic thing going with creatures in the wild vs those that are urban. The grief is mostly for the latter, who have to deal with the people who see them as "trash rummagers" and "thieves", and treat them harshly, instead of seeing them as the "recyclers" they are. They'll never acknowledge that cities with goblins living nearby are always cleaner.