I mean, thanks to the African Royals they already have unique units and techs.
They just need a settlement, possibly a feitoria, in some maps. You can add them almost anywhere.
EDIT: I’m serious.
The african kingdoms shaped the portuguese alliance the same as every other minor civs, with a unique unit (the Canoneer) and unique techs (church organs and Portuguese Crusaders). You could easily place them in many coastal maps of the different continets
The Portuguese are a playable civilization, there is no precedent for a playable civilization becoming a minor civilization.
Could you explain what you are suggesting?
Ok, thanks for clarifying. 
It is sarcasm. Due to Portuguese civ feeling like they have been neglected.
Honestly, though, wouldn’t it be nice if a secular feitoria native site could be added to reduce the Jesuit spam in Asia and Africa?
Do we really need a single minor civ with sites in West Africa, East Asia, and Brazil all at the same time?
Do you want the enemy to ally with the Portuguese settlement against the motherland Portugul? Especially when those Portuguese overseas have official authorization and sponsorship?
You might as well make the Chinese immigrant villages in Southeast Asia settlements, at least they were not governed by the Chinese dynasties. Even so, this is still the last resort.
Actually this might be fun for the unknown map.
But why? They’re already a main civ in the game. You can ally with them by being allies with them in a normal game. If they added a main civ as a minor civ, they could do it for all the mains civs, but it would be confusing and thematically weird.
Yes, they could add minor civs for all the main civs, especially revolutions, in the unknown map. This will make the game wacky and interesting. They would only provide their royal guard/most iconic units and a bunch of upgrades that are civ specific.
Lmao. Or just replace the mediterranean british by Portugal.
The motherland Portugal needs to “ally” with Portuguese settlements in order to gain support from her subjects. lol
The Aztec, Iroquois, and Sioux settlements were cancelled, probably because the dev expressed their unwillingness to see such a phenomenon in the game.
Semirelated but, with triggers Portuguese can train Besteiros but Spanish can’t train Conquistadors and that makes me sad 
Edit: a "change train location " trigger would be pretty cool