I think there is some trick to deduce that there are no other myst civilisations in the game...
But maybe thats only possible on other difficulty levels?
When the AIs go fishing, agriculture, mining or other starting techs, they do not get the 20% bonus, so if you play on a difficulty level where the AIs lack agri/tw/hunting etc, maybe enough of them go for such techs so the global GNP is low enough?
The boudica map in the isolation workshop thread has the possibility to settle on one riverside wine and work another, so that is very likely to give you a religion.
The map I posted recently (Monty Island) give you the opportunity to settle on riverside incense and work a oasis.
But even in those circumstances, you can lose if the AIs with myst settles their second city fast and work alot of commerce tiles...
Only way to be sure I think, is to make sure no AI has myst.
But maybe thats only possible on other difficulty levels?
When the AIs go fishing, agriculture, mining or other starting techs, they do not get the 20% bonus, so if you play on a difficulty level where the AIs lack agri/tw/hunting etc, maybe enough of them go for such techs so the global GNP is low enough?
The boudica map in the isolation workshop thread has the possibility to settle on one riverside wine and work another, so that is very likely to give you a religion.
The map I posted recently (Monty Island) give you the opportunity to settle on riverside incense and work a oasis.
But even in those circumstances, you can lose if the AIs with myst settles their second city fast and work alot of commerce tiles...
Only way to be sure I think, is to make sure no AI has myst.
tiles and slider at 80%" 
