I agree with everyone who says there is little incentive for Detroit to do this deal or any deal like this. And for that reason, I don't think there is anything to this rumour. My guess is that they were preliminary trade talks but they never became anything more than that.
It's always dangerous to sell away your draft picks for money. It consistently works out against your team in the long. Even though this is a weak draft, there will be some solid players available at their pick slot. I think the pick is more valuable than ridding themselves of two years left on Rip's deal.