I did this one campaign which was a hexcrawl where the party was shipwrecked on an island purported to hide the lost city of gold.

The site of the shipwreck was home base, but the party obviously wanted to explore. There were some NPC crewmate survivors, so they would assign them to work on projects while they were exploring. I would always tell them that "some guy" was working on their stuff.

Cut to a few months later when they have a sort of mutiny on their hands. It seems that one crew member in particular was fed up with how much work they had to do while the party went adventuring that they turned the crew against the party.

The mutinous ringleader's name? Sum Gai

Terror Island writing tip: Specify that characters have names. This makes them more relatable. (That's the title text for that comic.)

I'm imagining something like:

Player: I ask the NPC for his name.

GM: He tells you his name.

"How do you spell that?"
"I dunno, how do you wanna spell it?"

I just use the MST3K approach: This is Blast Hardcheese.

https://www.youtube.com/watch?v=RFHlJ2voJHY

Our player who likes doing this to the DM: "So they're giving us horses? What are the horses' names?" Our DM: "....no. You choose."

Id just use a random name sheet. Get some fancy names print em out sprinkle in a little setting specific stuff and roll dice for it. 100 names each and a D100 will do the trick, if its not fitting at all, just roll again.

Any npc I make up on the fly is 100% an orc. I can just put bodily-fluid+weapon together and boom, named.

Oh, him? Yeah, that's the Orc bartender PissMace.

I need to start doing this to my DM