USB 2.0/UAC2 DACs & Re-Clocking USB
Since USB 2.0 audio/UAC2 does not include a sample-clock, there is no clock to “re-clock” that relates to the audio signal/data.
All USB DACs receive data into a buffer and then use a local* clock (i.e. within the DAC itself) to clock sample data out of that buffer at a rate specified in the UAC2 pre-amble.
UAC2 does include time-sync data, but this still isn’t a sample-clock and is used simply to allow synchronization across multiple UAC2 devices.
Thus, all USB DACs are already “re-clocking” their USB inputs (and you’re only as good as your final clock).
A “USB Re-clocker” only re-clocks the USB clock, which is not related to the audio or sample clock**. There may (or may not) be other artifacts (good or bad, measurable/audible or not) resulting from the use of such devices, but they’re not because re-clocking the USB clock has any correlated effect on the jitter of the sample clock in the DAC (unless it is incompetently engineered or there are other issues in the overall USB system being employed).
NOTE: That this situation is completely different for S/PDIF or AES connections, as those protocols use a bi-phase clock as part of the signaling scheme and that bi-phase clocking IS the sample-clock.
*Some DACs can use an external word or sample-clock, but this is still unrelated to the timing/clocking of low-level USB transfers.
**It is technically possible to build one that was, but you’d have to be a muppet to do it as it is much more involved than simply using an appropriate local clock, introduces lots of other issues, and is unlikely to be as accurate anyway.