Are they Vlad - the way you would prove that it to point to an existing humanist school. But you can't, because there aren't any.
As far as I am aware the only free schools that have been allowed to be created with a distinct ethos are where that ethos is either religious or specific educational philosophies (e.g. Steiner, Montessori).
Yes there aren't any because the Humanist refuse to set up schools...in order to complain they can't set up schools ?
Secondly You have been selective in your drawing from the government guidelines. Let me supply a fuller version of your second paragraph.
''Faith free schools, free schools with a
distinctive educational philosophy or
world view (including Steiner, Montessori and Maharishi) and integrated free schools If you are proposing to set up a faith free school (either a school with a faith ethos or a school designated as having a religious character12), or a free school with a distinctive educational philosophy or
world view, you should note that: • All free schools are expected to be inclusive, including those with a designated faith or faith ethos. The requirement is tested rigorously at every stage of assessment and ‘pre-opening’ as well as after schools open;''
source:https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/579906/Info-How_to_apply_to_set_up_a_free_school_guidance.pdf