Do you plan to change SQL data type interpretation for the Origam Memo data type? Memo data type is actually represented by ntext in SQL server. According to https://msdn.microsoft.com/en-us/library/ms187993.aspx ntext will by removed and replaced by nvarchar(max) in future version of SQL server.
Yes, the default behavior of the Deployment Script Generator will be changed to produce nvarchar(max) instead of ntext.
Anyway you can manually change the type in the script by yourself. You are also free to change the types in your existing tables. Both database datatypes work with the Memo type in ORIGAM.