Usually we get a big patch with lots of fixes, improvements and balancing roughly every 4 months.
And I believe this week would have been perfect timing, right after the end of Red Bull and 1-2 weeks before start of Warlords tournament.
Otherwise my prediction is either next Tuesday, or maybe the aoe2 DE anniversary date, 14th. Or at end of november after Warlords finishes tho I feel that would be such a long wait compared to when the last real patch was.
Also currently there is quite a game breaking issue since the last hotfix, where half the recorded games are randomly unwatchable, which can have a big negative effect on community tournaments for example.