If I remember correctly they hired Luoshuang to do exactly that, to implement a official gpu lightbaker. But when this will happen only @Luoshuang can tell us (pls).
Tbh I wouldnt hope for that to happen probably for the next 1-2 versions of the engine (if they do this earlier I will be very happy too). The problem is that, the prioritization of the features they implement depends on what they need to do for their games and not that much for the developers. Which means that if you want something its possible that your feature request and such will go very low on priority for them to implement or basically never hear you.