I have several cousins who work at the LEGO US headquarters in Enfield, Connecticut. One cousin is or was a customer service representative who responded to letters from children like Luka. She loved her job... I'll have to find out if she's still working there.
To an extent, it creates a person to person relationship that the kid will likely never forget.
I saw a special once on a guy who works for Lego and all he does is go around the country and abroad, building humungous Lego displays. The guy grew up building Lego stuff and now he has a job paying him for what he loves to do. How cool is that?
It sounds like your cousins have a job well suited to them. It’s a beautiful thing when people are working a job that allows them to fully use their passions and strengths.