Vote for this answer if you think the Bitcoin site should keep the existing scope that encourages questions about alternative cryptocurrencies (except those which are more appropriately posted to their own dedicated graduated SE site, such as Ethereum).
Other than Ethereum, there is no other Stack Exchange site relating to cryptocurrency that is guaranteed to stick around. Proposals in Area 51 (eg the Blockchain Technology one) are of little use to people who want their questions answered until they at least reach public beta. Even sites in public beta (such as the Monera one) may not exist long term.
The choice of name for the graduated Bitcoin site should be made once a choice of scope has been finalised.
ps: If you see further implications of reducing the scope of the site, please edit them in to this answer...