Tiles need to actually be destroyed through powers such as MThor’s Red, Yellow or Blue for the code to register them as “destroyed” in order to use Gorgon’s Calculated Strikes.
You also need to have Gorgon positioned ahead of MThor (so center, or left, with her to the right) or her “bug” means the game code will not register the tiles destroyed by her passive as having been destroyed on that turn.
It’s possible the extra tiles removed/destroyed in a row or column through a match 4 do count/register for Calculated Strikes, however, that doesn’t help you if your turn does not continue after that match 4.
So when setting up your team make sure you position Gorgon front & center, or at least to the left, with MThor to the right, or you won’t gain the benefit of the destroyed tiles for Gorgon.