Are there limitations on using pg_dump on a materialized view such that the data won't be included in the results?
You can not reload data manually to a MV, so it doesn't make much sense for pg_dump to dump the data itself out for a MV.  

If you dump the underlying table plus the materialized view, the dump file should load correctly by loading the tables, then refreshing the materialized view from them.  I don't think there is any simple way to give it just the MV name and have it include the dependencies, you have to track those yourself.

If you want the materialized view restored as a stand-alone table, you can stitch those together yourself.  Get the definition of the materialized view from pg_dump -s -t a.mv, but then you will have to edit it to make it create a real table, not an mv.  Then you can dump the data itself with

\copy (select * from mv) to mv.txt


And load it back on the other server with

\copy mv from mv.txt