Here's what my CLI said when I logged in today. It's likely said this for a while, I just never noticed it before. I'm running build 19077. I looked at my session logs, and it doesn't say anything about no swimming pool on any day, including current session, on which this happened. I did not magically whitelist in. I checked that too.
Let's cannonball in the swimming pool.
There is no swimming pool in this clan.
In the pool, flipping over.
Doing handstand in clan VIP swimming pool
In the pool, diving for treasure.
Diving for treasure in clan VIP swimming pool
Getting out of the pool.