For SFW, feral wolf characters are allowed but you will still need at least one wolf to be mostly physically anthropomorphized beyond having sentience and the ability to communicate with non-feral characters in order for them to count towards the “anthro” in Rule 3.
For NSFW, while the Harkness Test is the standard that most Furries use and passes in your example, with recent vague itch.io policy changes we are worried that this example would go against their “animal-related” policy. https://itch.io/docs/creators/faq#is-adult-content-allowed
We will email itch.io to see if they will allow such content but are highly doubtful they will respond to us let alone give us clarification to allow it. For now we will have to prohibit Harkness Test Passing Feral NSFW but will contact you if we do get a response.
Let me know if you have any other questions.