> A prominent feature of US politics (and indeed culture) is constantly setting such targets and then chickening out and moving the target back as the time approaches.

I'm not an American, so I want to check with this: this is normal for the broader culture? Not just Musk?

Musk is an extreme case but the general pattern is pretty common. See for instance rules passed in various jurisdictions to the effect of "a budget must be passed by date X", which then is circumvented via loopholes or changing the law so that deadline no longer applies.