Particularly for critical events like the power levels: if we don't have the power levels, or the user who is about to change them might unknowingly lose power, we should prevent that request from going through. An example is a homeserver sending a partial/no power level event and the user modifying some permission within that - because we copy the event from cache, riot will take the empty object, change the permission, then send over the new object. This leads to the user losing power unknowingly.
Particularly for critical events like the power levels: if we don't have the power levels, or the user who is about to change them might unknowingly lose power, we should prevent that request from going through. An example is a homeserver sending a partial/no power level event and the user modifying some permission within that - because we copy the event from cache, riot will take the empty object, change the permission, then send over the new object. This leads to the user losing power unknowingly.