Not really, the Game Blaster had no sample playback and was based on two Philips SAA1099 synthesizer chip; those chips and thus Game Blaster compatibility was removed already in the Sound Blaster 1.5 cards. A Sound Blaster as it is known today has nothing in common with the Game Blaster.
That said, it's more likely that the project doesn't support it (yet) because it's still much easier and cheaper to obtain a Sound Blaster than any of the other cards, since it was ubiquitous. GUSes typically go for hundreds of Euros these days while SBs can be had for much less than hundred.
Yep, just look on ebay. It's completely crazy. And people actually buy them for that price, too, it's just not offers sitting there for years without a taker.