well, i think it's a good sign that they invited you. this shows that they know you and the phoronix site, they know what amd is actually doing in the linux segment and they know your impact on the linux (graphic) scene. hopefully, they "need" you to spread good news^^. moreover it's a sign that they keep looking at linux market, looking what their competitors are doing such as intel, via and amd.
at least that's my interpretation/hope, so let's be optimistic