Yes, but incalculable butterflies mean that small things will be different. And if you've read any summary of the assassination you'll know that it took a ridiculously convoluted series of events for it to occur, making it extremely susceptible to butterflies.
Even if it went as IOTL there's no freaking excuse for OTL Presidents past 1920.
Things that could have changed:
Princip decides not to stop for a sandwich, thus he doesn't run into the Archduke
The Archduke's motorcade doesn't take the wrong route and instead heads for the hospital
The motorcade stops in a different area, so Princip isn't as close and the motorcade can back up before he does anything
And there's even more. All of these could easily have been effected by butterflies, unless we're saying that a person getting a sandwich is 1914 can't be effected by events in 1912.
As for beyond 1920, that is certainly butterflyicide. With a POD in 1908 every President after Eisenhower but maybe LBJ wouldn't even be born. Unless again we're proposing that every person who met IOTL was fated to meet and that every sperm will be the one that fertilizes the egg (and given the fact that it's a million to one or billion to one shot that seems unlikely). And that's not even getting into all the political and social changes.