Yes, it does, though for slightly different reasons. Mainly, it can break pages with first-party scripts that depend on blocked third-party scripts. I've encountered and reported a few of these while testing the feature.

I wonder how difficult it would be to duplicate the Google Analytics object with blank functions for just such scenarios.

Rather than "ga is undefined" the ga.whatever function would just return without sending any data.

Do any third-party script blocking systems do this?