It can happen, but I don't know how regularly. From personal experience, my husband's visa was approved and he entered with a B2 to visit me before coming back to finalize the move. No questions asked at the border. We did mentioned we wanted to do this at his interview, and the officer saw no issue with it. I am not sure if he noted it somewhere, but my husband was prepared with a ton of documents proving his return to his home country, yet he was waived right through on his B2.
To elaborate, he was approved in late October. He came for Thanksgiving in November. Then he moved here in March.