It is a play on the joke of Half-Life 3 confirmed by out side of the pond. A sad, sad, depressingly sad, joke. : )
Now to get off an tangent about Muggy and FO4 Confirmed (They just did it and we didn't see it!) I'd have been a bit more interested in seeing them allow direct tip jars associated with one's hobby more than this to see how well it goes; as most of the time you test the waters before jumping head over heels in which seems to be what has just happened. Though I could be wrong and they are testing the water with this update and seeing how it goes. This is un-charted, some what but I'm not going to go into it, waters of selling game modifications make by folks with no gain in mind originally.
We might even see some Moorwind, Oblivion, FO3, & FO-NV modifications done with some professionally quality. Or none at all. We'll see. : )
Though I do hope that with more funds this brings in more modification maker protections from Beth. Had a bad experience lately watching the ship of "You'd be there for us like you said." hit rock bottom with Arma's community sadly.. Really don't want to see that here.