Yes, this does indeed work very well, as does adding a few truffle shavings to the mixture and keeping it in the fridge for a day before cooking the egg bites. It's just that a lot of people don't want to splurge on truffles. They are expensive and hard to find in many places. In that case, truffled cheese and truffle oil are the next best thing.
But that same recipe is still very nice if you don't add any truffle at all. Or experiment with herbs. A little chopped basil, or a pinch of paprika, or cracked pepper, or curry powder. All of these will work.