Do we have any reason to keep the old endpoints available?

Would it make sense to make it a string substitution instead?
Right now most of us define the TD_API_SERVER environment variable to set the endpoint for working with staging or locally running API server. I am pretty sure lots of us do:
$ export TD_API_SERVER='http://api-staging.treasuredata.com'
$ export TD_API_SERVER='http://api.treasuredata.com'
hence prepending the protocol part of the URL: "http://".
But NEW_DEFAULT_ENDPOINT is defined as 'api.treasuredata.com' without the protocol.

The way the code is written now, the api-import would not be used since '\@host != DEFAULT_ENDPOINT'.

My knowledge of ruby syntax is still basic but I am sure something like this exists: 
opts[:host] = @host.replace("api.treasuredata.com", "api-import.treasuredata.com")
or even:
opts[:host] = @host.replace(NEW_DEFAULT_ENDPOINT, NEW_DEFAULT_IMPORT_ENDPOINT)