Here is a Canon EOS R7 vs EOS R8 comparison review, and a highlight of…
Tamron SP 150-600mm F/5-6.3 Di VC Product Pics

Source: Dicahub (translated).
pixelistes (translated) published 9 pics of the Tamron SP 150-600mm F/5-6.3 Di VC lens. The lens is not yet available but you can get notified when it can be pre-ordered or is in stock. If you want to know more about the Tamron 150-600mm a good starting point is the lens brochure (PDF, download here).