Personally , I don't think there should be an ICO without whitepaper. The whitepaper bridges the gap between an investor and a company. Can we say a ICO without a whitepaper is a scam? Or what can you say about an ICO without whitepaper
The purpose of the whitepaper is to explain what the ICO offers. All the details are there. So what are we supposed to expect? No product but you'd be offering an ICO for nothing? That sure most looks like a cash grab and an exit scam. Some scammers even try to copy other ICOs whitepaper to look legit.