Duncan pointed out on IRC:

kowey: so on pull we can add a note about the remote repo being unhashed,
perhaps that also a useful time to point out that the local one is also unhashed
it's a slightly less frequently used operation, so less annoying place to add
messages

This is not quite as important as issue1583, but it's worth doing.

Scenarios where this may come in handy:
- server side not yet upgraded to hashed
- server side upgraded to hashed, but local is still traditional (pre Darcs-2.3 get)

Is this still a problem?  Are there still lots of unhashed repositories in 
the wild?

I'm not sure of why that would be a problem, since pulling is as fast
from an old-fashioned repository as from a hashed one.

When getting from an OF repo takes ages because there is no hashed
pristine retrieval (hence lazy get is impossible), yes we need to
explain to the users why it is slow, but in the case of pull I don't
see why.

guillaume

I think the motivation behind this feature is that it would help spread 
awareness among users with pre-existing local copies that the remote is 
still unhashed.

Yes but there's not much you can do when you see such a message if the
remote old-fashioned repository is on a machine that isn't yours. To
me, that's just one more message that would get in the way.