Accepting this altcoin would be just as voluntary as accepting Bitcoin. So no, there's no enslaving going on.
Even if implemented, you could refrain from accepting free coins or payment in these coins, so there is no need to feel threatened by it.
Nobody of the capital owners will accept these altcoins IMHO.
The enslaved are the people that are forced to work in order to enrich the people that don't work.
Partially true - if accepting altcoins will be compulsory, this idea have no difference with taxation.
But assuming that main production factor will be the capital (robots) and not the labor, no people will be force to work, just bourgeoisie forced to share production means.