[R&F] Military Alliance, bug or feature?

[Tech Osen]

When you have a level 3 military alliance any unit you produce gets a free promotion. But whenever I upgrade a unit it also gets a free promotion the next turn. I kindda doubt this is intended but it just sees the upgrade unit as a whole new unit?

 

[Trav'ling Canuck]

When you have a level 3 military alliance any unit you produce gets a free promotion. But whenever I upgrade a unit it also gets a free promotion the next turn. I kindda doubt this is intended but it just sees the upgrade unit as a whole new unit?

The game sees it as a new unit (see the announcement about the new XP gained equal to the XP of the old unit) so this treatment makes sense.