In the video event, Tim mentions more updates at WWDC next month - I suspect we will see a M4 MacBook Pro then.
Haven't they been announcing Pros and Max's around December? I don't remember. If they're debuting them at WWDC I'll definitely upgrade my M1. I don't even feel the need to, but it's been 2.5 years.
November 2023 for the M3 refresh, M2 was January 2023 if I remember well.
Mac Studio with M4 Ultra. Then M4 Pro and Max later in the year.