Bunching and rippling of skin 3.5 weeks after breast reduction. Will I need a revision? (photos)

Although your concerns are understandable, I think that you may already have a good understanding: it is too early to evaluate the outcome of the procedure performed.  I would expect a large amount of the "bunching and rippling" of the skin to smoothen out over the course of the next several months; the question that cannot be answered online is whether or not the degree of improvement will be sufficient, or whether revisionary surgery will be beneficial. Your plastic surgeon will be your best resource when it comes to more specific thoughts, advice, and/or meaningful reassurance.Best wishes for an outcome that you will be pleased with longer-term.

First of all, congratulations on your breast reduction, MeliaK!
It’s still too early to tell if you’ll need a breast reduction revision because you’re still experiencing a lot of swelling at this point. The results you see right now can still change in a few months’ time.
I suggest that you wait for about three to six months before you start thinking about breast reduction revision. For now, just continue following the aftercare instructions that your reputable and board-certified plastic surgeon gave you.
Recover well!