The German High Regional Court of Munich has established that without a specific release date it is not possible to offer a pre-order. As reported by Eurogamer, a consumer protection group noticed the problem when the Media Markt dealer avoided giving a precise marketing date for the Samsung Galaxy S6 pre-orders. Not only did the Supreme Court of Monaco ruled against this practice, but applied it to all products across the country, including video games.
Here is what was said by Wolfgang Schuldzinski, CEO of Düsseldorf Consumer.
When consumers order goods on the Internet, suppliers must specify when the goods will be delivered
This ruling applies technically only to Germany while the United Kingdom and the United States do not currently have such regulations. It is not clear what would happen if a publisher has to delay a launch for any reason, or how the rule could apply to projects funded by crowdfunding.
In short, it still seems a rather vague thing, we await new information on the matter.