I just did the chat function and they said the slides and area around them were closed through September 14th and in the meantime they will shuttle you to Paradise (Pixar) Pier Hotel in golf carts to use their pool/new splash pad area though the regular pools at the
Disneyland Hotel are also still open just not the slide area.
I will be there the 7th to 11th with an almost 2 year old and an almost 4 year old so I have to decide if we will stay at the Disneyland Hotel pool and just use the pool area or if we will take advantage of being able to try out the new splash pad. My almost 4 year old loves slides and I think she would be fine with a lifejacket on the slide at Paradise Pier but I also love being able to have food and cocktails by the pool which as far as I know is not yet available at Paradise Pier.