About fireball beeing, in the game or not. Honestly you wouldnt be able to tell by just playing 25 minutes. Specially if you have to start with a new game.

They dident even get past the druid encampent after all.

About wild magic potentially not working.... The odds of a wild magic surge are crazy low. If you arent forcing a roll the odds of it showing up are a 1 on a D20 so 5%. And only lvl 1 and up spells count for that, so not for cantrips. I wouldnt be surpised if the number of lvl 1 spells cast in that demo were less then half a dozen. times 5% of it happening per cast and the fact that it dident happen yet isent really all that strange tbh...