- this is a generalization but Portuguese language and culture originates from Galician (they belonged to the same Kingdom during the middle ages until Portugal broke off from Galicia and formed it's own seperate identity, however culturally they are almost identical and Galicians during this time period had more in common with Portugal than Spain).
- During this time period, Galicia did want more auntonomy from Spain, so there possibly could be support to leave Spain altogether.
- As for Portugal wanting to annex Galicia, I don't know. Otl, Salazar supported Franco and was a staunch anti-communist. I wonder if there is a situation where Portugal is dragged into the war, occupies Galicia, and refuses to hand it over to Franco after the war?