If the 9th gen consoles launch with BC in 2020, is there any reason to produce 8th gen consoles beyond 2020?

[Farsala]

It will depend on the individual companies goals. If they want to make more money now, then to keep selling last gen consoles is a no brainer. If they want a faster transition with possible more money later, as I expect MS to want more, then they will phase them out quicker.