I've never been a huge fan of Easter Eggs. From a risk management and QA point of view: there are a lot of things that can go wrong in a software project, why deliberately add something else not asked for, even if there was only a 1% probability that it would break? It just seems that the downside risk massively exceeds any potential upside. If something actually fails because of it and you have to write the postmortem, what are you going to say?
I started at Apple a few years after the original author, and by then the policy on Easter Eggs was that they were allowed within reason, but had to be declared internally, so they could be tested. There were even "official" Easter Eggs that listed all the engineers in the team.