From my experience, yes, there will be specific verbiage given if a particular ticket is non-refundable. Unless stated, consider it a refundable ticket.

I've gone around and around with Amtrak when I had concerns about their wording. Calling Amtrak does not clear up the nonsense in that statement. They claim that is all that is said in their system and they have no additional information. So if they try to pull something later, it will not hold up since it wasn't disclosed. Now proving something wasn't said might be difficult, but it appears Amtrak has learned a few tricks from it's funders (gov't).