Miners believed they represents Bitcoin Core, otherwise it wouldnt make any sence. But unfortunatelly miners got tricked. Next time miners should request signature of all Bitcoin Core developers over hashed text before providing their signatures. The number of Bitcoin Core developers saying no hard fork possible and for example luke-jr, one who signed this deal encouraging others on reddit post to create website to sum reasons why hard fork is dangerous for Bitcoin clearly shows even luke-jr intentions are not to make the deal happen (first SegWit then 2MB hard fork activated in July 2017).