EvanTheJet: I think this would be a very nice treat to coincide with the release of the GOTY edition. I thought the soundtrack for BaW was great. Unfortunately, I haven't heard anything to suggest this will happen, but I will cross my fingers anyway.
Both the Blood & Wine and the Hearts of Stone soundtracks have been added to the goodies pack. =)
bricbrac: Counter argument: If CDPR didn't intend to bundle the new soundtrack as an incentive with the game why wouldn't they then sell it through their shopfront (GOG) as a seperate item? W3's soundtrack being available for purchase didn't keep them from bundling that, for instance.
Hickory: As an incentive? The DLC has been out for ages. The fact that the DLC soundtrack is only available for purchase off-site tells me that it will not be available on GOG shelves for free... yet. Maybe at a later date, but not in the near future.
BTW, soundtracks for both the expansions went into the incentives packs today.