Depends - I think 2 sessions in a week is a bit low because but I went for a weekend two months ago and it was 2 sessions for 3 nights so 3 sessions for 4 nights would seem fairer.
I was tempted to cancel but it was actually really good, they let you in quarter of an hour early for your slot and were not bothered at all if you overstayed so actually had nearly three hours which with drying, getting changed time etc, was more than enough, particularly because you didn't have to queue for the rides. It was a much nicer experience going down the rapids alone rather than as part of random stranger body soup!
However they didn't have the wave machine on and because they were limiting the hot pool you couldn't stay in there very long which was a pity in the night time session!
So it depends what you like doing. If you have small children and spend most of the time in the pool then yeah it will be a bit of a waste. However if you have older kids or like doing other activities and are happy to just have two sessions it's actually a much nicer pool experience than normal and I preferred it. Ideally when they go back to normal I would actually prefer them to keep the timed booking slots and limit pool capacity, but increase the number of slots you can book to once per day (or maybe one fewer).
Slightly off topic but I don't get the poster above who says they justify the expense by swimming 'at least' twice a day? What an absolute faff to get from your chalet, get changed, swim, shower, dry and change again, then go back to chalet, and then repeat multiple times - what's the point? Half your day is surely spent travelling and changing! I understand spending a few hours in the pool once you're there but not going back and forth multiple times!