You don’t need to log M+ for it to show up in Warcraft Logs. They pull data from leaderboards which includes even lowly +2 Necrotic Wake that was missed by 30 min O_o
I didn’t realize this until I tried to look up the logs for a guy that was asking about how to interpret them in this thread. He had no logs at all, yet all his runs were there anyway (from leaderboard data).