That's not true!
Let n=3k, for some positive integer k. Since all lynches are assumed random, there's a 1/3 chance the cult recruiter will be among the first k players lynched. Prior to this lynch, there will have been at least 2k+1 players alive and at most k cultists (including the cult recruiter), giving the town the win. If it's possible for town to win while not lynching the cult recruiter in the first k days, town will win more than 1/3 of the time. This requires 2 cult out of 2k players to not be a cult win (i.e. town lynches cult recruit every day but day 1), which first occurs for k=3. Therefore, town wins more than 1/3 of the time for any number of players that is a multiple of 3 and at least 9. I don't know if town wins more than 1/3 for any other number of players (and I didn't brute-force check any to try to find out), but it definitely works for those.