Correct. But. If the water level gets high enough, Even close to the ‘brim’, the normally taut above the water cover will be stuck to the pool water and have a puddle on the top side. So the pump can effectively drain the pool, through the mesh cover, without having to pop a corner.
So you don’t *need* the cover pump but it could still be useful. My 98% mesh cover took almost a day to drain when it rained. It did everytime (providing that the pool water was down enough), but it was sloooooooow. A cover pump would have sped that along *and* stopped another 300 gallons (?) from entering the pool.
Or just let it ride and drain 12-18 inches once or twice over the winter. We get about 3 ft of off season precipitation here. Your choice if you want to drain a foot 3 times, 18 inches twice, (or any other equivalent) or let a cover pump help before it gets in the pool in the first place.