My husband asked the dr. that, and the answer was "it wouldn't hurt", i.e. he wouldn't be in any danger of his bp falling too low, and yes, probably it does provide a little protection in case the bp starts going up again.
But my husband regularly checks it....maybe I'll propose going off it for a trial run....I don't know, but at least it's been consistently low for some weeks now, which it hadn't been for so long.