cambridge gives 3 meanings of fetch
to go to another place to get something or someone and bring it, him, or her back
to be sold for a particular amount of money
to hit someone with the hand
this post says
"'Fetch' hasn't happened because people still try to make it happen," he said. "If people are still gonna try to make it happen, it's not gonna happen. I think that's a good PSA to do. Stop trying to make fetch happen! It hasn't happened because you're trying to make it happen."
So just apply that to the word "fetch" and we might make it happen in the next 20 years or so.
"To clear the record, it's not that I don't want to have a Mean Girls reunion," he insisted. "I'm just tired about everyone asking about it. Because if I knew, you would know. It's not that I don't want there to be a reunion. It's just I don't know when, so that's what I always say. Mean Girls reunions are like 'fetch.'"