I suspect they fled Angola and Mozambique. If they are largely people who opted not to return to Portugal in 1974 and went there instead it would explain why they are so far right wing.
The most of the Portuguese had a good relation to the native population in Angola and Mozambique and return to Portugal after the independence of the colonies. But the right-wing people go to South Africa, not all were fascists, but many. The South African government made all the whites in Angola and Mozambique, the offer to go to South Africa. Some did, but most do not.