Hello Catiel56 -
Currently eBay has this set as noted, you can opt in or opt out again if you decide not to use Business Policies. Unfortunately, we are unrelated to eBay and so have no means to say what eBay may or may not decide to make mandatory in the future. While they do strongly suggest that users make use of business policies, it has not been stated whether or not eBay will require listings to use these policies in the future.
If you are opted in at this time, eBay provides warnings from their API stating that the policies will become mandatory, however, no such warnings occur if the related eBay account is not opted in to Business Policies.