Is there really potential for Bitcoin to metamorphosis into every altcoin?
"Bitcoin" will not morph into anything, instead additional functionality could be built on top of the secure decentralized Bitcoin protocol with its immutable ledger acting as the settlement layer. This will make a lot of altcoins obsolete, but most of them are already useless and obsolete as we speak. The only reason why they stay around is to get pumped and dumped.
As for the part about "every" altcoin I have to say it will never happen. Alternative cryptocurrencies (despite what they have turned into today) are going to stay relevant, the idea is to explore other technologies based on what Bitcoin introduced but with differences in hopes of improving the technology.
Unfortunately today the definition of altcoin has changed into something we pump and dump and has no real underlying value or technology but that doesn't change what can happen in the future with some new altcoins that may show up from some competent developers.