In one of our Sandboxes we noticed one of the picklist fields(not the values, the field itself) is not under 'Picklist available for Editing' section while in other Sandbox it's still there.
But when we retrieve the object metadata file via Migration tool(from the same user account), the field is there for the record types. It's missing from the below Setup interface.
Best Answer
Why don't you try out by creating another business process. Hope that will work for you. Once you have created this business process you will associated it to the record type upon creation or edit.