Am I correct in this assumption?

My local library has a monthly chess club meeting and last month, they were discussing playing the KG against the Sicilian. Am I mistaken or is this simply the McDonnal Attack or an accelerated Gran Prix Attack? Any ideas on this would be greatly appreciated.

The DB I accessed is calling it a Gran Prix Attack (B21).

This is an example line and it gives wins for Black whether White plays Qe1 or Qxd8

yep just the Grand Prix Accelerated

Sorry, never heard of it.  Interested in the answer though...

King's Gambit is not possible against the Sicilian.

If you mean 2.f4, then yes, this is a move, but 2...d5! is widely considered good for Black.  This is because the Tal gambit 3.exd5 Nf6 4.c4 e6 gives Black great central activity for the pawn, practically no one wants to play this for White, and if White does not go into it he could end up in an awkward position that requires creative looking development just to show equality, e.g. the dreaded "Toilet Bowl" variation.

Grand Prix Attack would be 1.e4 c5 2.Nc3 Nc6 3.f4.  The inclusion of Nc3 Nc6 takes away Black's quick ..d5 and this is very important.

Great. It seemed a bit odd to me that for someone puting together a chess club, that they would make such a big error.

I wouldn't say it's a "big error" so much as a little sloppy with regards to opening classification.  It's more important to understand the reasoning why certain move orders are not as popular.

True. This seems like one of those openings we used to call Coffeehouse openings.

Not Coffeehouse. The Grand Prix Attack was quite popular for a while, certainly amongst UK GMs and IMs, but antedotes have been found. It gets its name from the "Grand Prix" competition, which runs in the UK over the year, and is won by the player who gets most points in what are mainly weekend Swisses.

The fact that the "club" is advertising "King's Gambit against the Sicilian" tells me that the club is full of patzers, and probably nobody higher than maybe 1200.