Hi Gewora,
I cannot locate this information in the knowledge base at this time, but I’ve alerted Envato Support of this matter and this will hopefully be resolved soon. However, I can tell you that this policy is not new and that authors are not permitted to check purchase codes in order to activate / grant access to a purchased item. As stated earlier though, verification can be used in external support forums.
“The item, and all advertised sub-modules and features, needs to be functional right out of the box without user intervention.”
This refers to activating the product with a key, etc. which is not permitted. Yes, some user setup / configuration will be required - but it cannot include verifying the purchase. This is something we check for here and on ThemeForest.
Another staff member will be along shortly to address locating this information in the knowledge base for you.