If I'm not mistaken, this will be groupees first gog code, with a stealth release here tomorrow.
Sadly, I'll bet you $1 I am mistaken...
Nope, quite a few GOG games were in Groupees bundles so far, but most likely before you got into the sport, and most certainly ones that you already had.
The stealth release though thanks to a Groupees bundle would definitely have been a first, if true.
As for Day of the Tentacle
, I think that's another case of remastering by DF.
Jonny confirmed in chat: Deep Dungeons of Doom
Is that a Steam only game?