Not only do you not need to catch up with Disco, but the end of season 2 of Disco doesn't dovetail to the beginning of Strange New Worlds super-well when you watch them back-to-back; if anything, they feel like they lightly contradict each other.
Though if I were to recommend a single episode it would be "Through the Valley of Shadows" from season 2, which is probably the only "important" episode as far as Strange New Worlds goes, though the key stuff gets recapped in SNW.
The Short Treks episode Q&A gets some references in the series too, though if you don't watch it you likely won't realize you missed anything.
Fun fact: The TNG episode of the same name was originally intended to star Patrick McGoohan as Ira Graves.