The R system does not make anything obsolete, it is a wonderful addition.I'm sure they won't stop selling EF system from tonight. They kept 'officially selling' film cameras until some years ago too.
But I'm pretty confident their long term plans are the RF system.
My 20 year old L glass will still be here in 20 more years unless Canon invents new optics or their newer bodies outresolve these lenses.
I occasionally shoot film with my old 650 and A2e EOS bodies.
And my walkabout kit is a 2012 EOS 6D with 1990s 28-105 USM kit lens. The smallest imaginable full frame system with very good image quality.
Ordered the R last night with RF 24-105L and control adapter for my EF lenses.