Yes but what exact nations and units I don’t know, seems the British Raj/India will be there with its Gurkhas. Warlord put out this release date map; Armies of the Commonwealth should be out in Q3 2026
Asked for a clarification on this, they said to continue to use the army selection in the Core rulebook until Armies of the Commonwealth comes out.
I’m not seeing where it says you can add stubborn to any infantry or HQ unit in Soft Under Belly it only says on pg. 174 you can add it to “Special forces reinforced platoons” and then it list what theater selectors count as a “Special forces reinforced platoon” under each theater selectors special rules.