No, there are some licks that are only compatible with USX picking. For example, a repeating three note pattern on two adjacent strings, one note on the b string, and two on the e string. Picking pattern for this lick would be down-down-up-repeat. The two down strokes are a mini sweep. There are some others as well, like the Eric Johnson descending fives pentatonic lick.
Conversely, there are some licks that are only compatible with DSX picking. Take a 3-note repeating pattern on the e and b strings. One note on the high e, two on the b string. Picking pattern would be up-up-down-repeat. The two upstrokes in a row are a mini sweep.
But you are right that many licks can be done simply by reversing the picking, or adding in hammer-ons/pull-offs to make sure every last picked note is a downstroke so it escapes the strings.