I feel quite the opposite regarding post-long run strides. I feel like they help to kick off the recovery process better.
My naive intuition here is that there are two things going on.
First, during the long run you've spent quite a while going repeatedly through a limited range of motion, and the strides help to open that back up again.
Second (and probably more importantly) the long run beats the muscles up quite a bit, but doesn't seem to strongly trigger the hormonal responses to put the body in an anabolic mode so as to fix that muscular damage promptly. If some some reasonably vigorous strides are thrown in at the end with incomplete recovery, maybe the mild increase in blood lactate levels help that hormonal response. Maybe you could get a similar benefit from just hammering the last kilo of your long run, but strides seem like a much easier solution.
I was first introduced to this practice by a 1500m world champion who swore that post-long run strides would (the next day) make it feel like he'd run 3 or 4 miles fewer from a recovery standpoint. I don't know if my physiological guesses are close to the mark, but I do know that they make me feel better the next day too.