These two AWP style games were advertised as appearing at one or two MG casinos, so if they appeared, and then left, they have "been pulled" in effect.
This is pretty rare, but has happened before. What is more common is for new games to launch with errors, usually involving the display, which are later fixed.
Mega Moolah launched with one such error, which displayed to players that they had won the MEGA Jackpot, and this was because a few frames were missing from the bonus wheel movie. This was fixed by a swift update.
I have also known games not to appear in the lobby on the date advertised, but they usually follow soon after.