Unless bitcoin becomes an umbrella term for all the cryptos, then no, it will not become the only currency on the interwebz.
In the future, there may be a single crypto-currency. But it will be one with many facets and many ways of using it. This crypto-currency of the future will be more secure than bitcoin, and more useful than ethereum, combined.
On the path to this "single" currency, we will see block chains join/merge. This will be a technology that will blow mathematician's minds.
We have not even entered the early-adopter phase. So, we cannot even place bets on which coin will become the universal currency.
Yes you are likely correct. He does specifically say that it won't be bitcoin in it's current form. It will be bitcoin many many upgrades from now, but will likely bear that same name.