Narrative, narrative, narrative. Every team and player who doesn't find immediate success as soon as they get good has to deal with it. LeBron, Dirk and the Mavs, Jordan in the late 1980s, it's pretty standard stuff. And then even when you overcome one hurdle, they just change the narrative. It used to be that Toronto choked early in the playoffs, but now that they're winning playoff series the new narrative is they can't overcome LeBron.
I don't think this stuff about pressure or whatever is nonexistent; it might have some impact on the game. But Toronto's much bigger problem is that they are facing arguably the greatest player in the history of basketball and they are down 1-0 and no longer have home court.
I seriously doubt they'll roll over and die, but even if they play at their normal level they still could lose now that they're in a hole.