Seems like Toronto won their series because they did the opposite. Decided Giannis would not beat them.
The difference is, Giannis isn't the complete player that Kawhi is. He doesn't shoot that well outside the paint and he isn't as good at finding the open man when doubled.
I do agree though, that it may be a little early to change their strategy.
The reason their defensive strategy didn't work was because the other guys hit their shots...so maybe put the pressure on them again. If they continue to respond well, then change it.