Event details
There's currently no recoverability story whatsoever; see here also: https://techcommunity.microsoft.com/t5/planner-events/the-new-microsoft-planner-meet-the-makers-and-learn-what-s/ec-p/4102511#M35
This is very unfortunate and the reason we don't have a ton of people using Planner!!!
- Same here. Without any means of recovery, it isn't suitable for anything serious.