Whether or not it's a misconception, and whether or not the US are faithful to the treaty while weaseling out of helping Ukraine, is irrelevant.

A treaty where the guarantor is known to give sketchy legal interpretations about why them backstabing you is actually faithful to the treaty they signed is barely more useful than a treaty where the guarantor won't honor their word.

The ripple effect is already there: many NATO country are now wondering whether the alliance is worth the paper it’s written on.