the second theory was based on: if poli has the bug where you get no system message during the day, and you have to backtrack to night to see it once day starts (like bleeder)... or even if poli receives system messages at night legitimately... the journalist will not see it, since the action is checking system messages at the beginning of the day.

I have tested journalist/informant issue and it does appear that they don't get politician alignments. I ruled out the first explanation you listed but I don't understand the 2nd.

politician wins with town or mafia, so he doesn't get a win notification for the same reason a fool or lyncher that wins with town doesn't. he doesn't own an alignment.

have you thoroughly tested the journalist/informant issue? its possible that he didn't change alignments the day he was investigated, or that he is one of those roles that receives its system message at night now.