I think it is safe to assume that GSN wanted to, at the very least, get better numbers for DWtS than they get for anything currently on their schedule - especially after buying the EW ad.
The question is whether this was a worthy gambit in the first place considering (a) the franchise is waning in popularity in first-run, and (b) BBC America already tried early-series reruns and had decided it wasn't worth their while to keep airing them even though they still have the rights.