I think it's apparent that no European airline will be operating their full, originally-scheduled timetable at any point during this summer.

As such, those that give the impression that they are keeping their "full" schedule in place past May/June are probably doing everyone a disservice.

I don't expect that there are many people making new bookings for the summer months right now - but some people may be using the ability to change existing bookings such that they are rebooking themselves onto dates/flights that KLM already knows it won't be operating.

It doesn't seem to be a bad idea to totally thin out the schedule for the next several months given current circumstances.

There is nothing to prevent KLM from adding back routes/flights as and when the situation evolves.