As you would expect, WhatsApp disagrees with the comments and research conducted by the Hamburg Commissioner. A WhatsApp spokesperson told us,
The Hamburg DPA’s order against Facebook is based on a fundamental misunderstanding of the purpose and effect of WhatsApp’s update and therefore has no legitimate basis. Our recent update explains the options people have to message a business on WhatsApp and provides further transparency about how we collect and use data. As the Hamburg DPA’s claims are wrong, the order will not impact the continued roll-out of the update. We remain fully committed to delivering secure and private communications for everyone.
With WhatsApp's stance that the Commissioner's ban is based on a "fundamental misunderstanding" in mind, we would assume that the company will take its chances in court and try to appeal the order.
For what it's worth, Facebook is giving users in other countries a grace period of sorts, after already pushing back the initial February 8 deadline. When you don't accept the new policy by May 15, WhatsApp will gradually reduce the amount of features you have access to until you're completely locked out, effectively forcing you to accept the revised legal document if you want to continue using the service. It will never outright delete your WhatsApp account if you don't accept, though.
We've updated the article with a statement from WhatsApp.