I say, steady on chaps............
All I can say is that I seem to recall this procedure back in the early 70's as a flying spanner on 747 Classics - or perhaps DC8's. I thought it was a safety precaution related to the weight of the bogie gear, so perhaps N/A on 737's and such like.
And yes, part of the "uplock check" when you went from UP to OFF was to ensure that none of the gear door lights (front or back) came on indicating something amiss; if so the handle went back to UP and stayed up.
And yes it went back to OFF when out of the turbulence.
And yes a lot of Ruddles County has gone under the bridge since then, so I'm always ready to stand corrected if I'm remembering it wrong.