When the game was announced on steam , it had an mark in voice/interface/subtitle in Portuguese-brazilian ,but some time after, the voice mark wasn't in the game , only interface/subtitle, and the voices are the original english voices.

Brasil is the 4° game consumer and have more brazilians players than frenchs players, so why fallout 4 hasn't voice in pt-br and the other languages has all the 111.000 lines of text voiced.

Because Portuguese is the new Latin. Only a small amount of people use it and the cost to translate outweighs the need.