He doesn't say 'replaced',
"I think we evolve to Bitcoin 2.0 or 3.0, using the same blockchain technology, but with a way to make the
new currency a truly stable medium of information that can be easily exchanged for goods and
services."
and "But will it be Bitcoin? My best guess is that it will not be Bitcoin as currently constructed but rather an evolved version."
Isn't that the idea - as with most software - to evolve?
Well, to a degree, if such software aspires to be at least a currency. Dollar is still a dollar, there was no dollar 2.0 or 3.0
I guess what I am getting at is that bitcoin has to stay the same bitcoin with 21 mil units just as a 1930 dollar bill could be redeemed now for goods and services.
If bitcoin changes, evolves, mutates, sublimates into something else entirely-most will feel betrayed IF "old bitcoin" would not be accepted at par (or better) with bitcoin 2.0 or 3.0.