Shield of Glory has an active Discord and there are reminders, but I tend to be in enough to get the in-game reminder and, I generally enter my teams early in the round.
Wild diamond was a killer! I had losing streaks far longer than my winning ones :D I think there are better bots and, incentive to be in Champions is higher, so people are pushing hard.
Yeah, the incentive is to keep using the one account, rather than having multiples. I wonder how many top guilds have multiple alts within them playing Brawls?