it's a norm
no need to be surprised even if the speculation above are 10% accurate.

Of course they will start planning for the next gen road map once the new console is released.
Else the R&D dept will just taking salary for doing nothing

Wii U was launched one year+ ago, it's it's expected for such info to leak out, most likely it's just leak info from the R&D dept, nothing is conclusive yet.

same thing for MS & Sony, I'll bet their R&D team is already planning & having some design concept for XboxTWO and PS5