Consoles are going to become a thing of the past. I think the next generation of consoles, in order to survive and maintain it's status as an up to date machine, will need to have the ability to incrementally update the hardware. Currently the PS4 was released in 2014. The hardware and technology in the console is 4 years old at this time. To the point that Xbox and Sony are releasing the PS4 Pro and Xbox One X. Versions of their consoles with updated graphics and other tech. Want the updated version? Fork out the full price. No upgrades.
In today's tech world we are improving almost daily. To the point that phones seem to be obsolete one year after their release. It won't be a good practice to release a console which you plan to be your flagship for the next 5-7 years when it would likely be obsolete in less than half that time.
I imagine consoles that will have a level of upgradability for lack of a better word. A base console, base CPU that's powerful for the time. The user can have the option to update the console's GPU, RAM, and storage capabilities by purchasing "add-on" upgrades that are easy to plug and play within the system. Sort of taking the customizing and expand-ability of the PC and making it easier for those without the know how to swap out and upgrade parts on their console.