In an emergency can you safely drink the water produced by a portable indoor dehumidifier?
Can it safely be consumed by my cats as well?

Probably wouldn't hurt to spray a little bleach on the coils and bucket and run it a few cycles first but boiling the water would do the same thing.

Look into the bucket that collects the water. Mine gets nasty. But if I had no water, I'd boil it and drink it.

It would likely be a good idea to boil and or run through a Lifestraw first.

I was eyeballing the sump pump wells in the basement and wondering the same kinda thing myself.

If I ever need it I'll run mine through my Berkey (I use Doulton ATC Super Sterasyl ceramic filters). Being in South Texas I can pull a lot of humidity from the air.

If you are worrying about a water source remember that the dehumidifier runs on electricity in a natural disaster you may not have power for several days. A better option is to super clean your bathtub, plug the drain and fill it. That is a lot of water to drink, wash, cook, etc. with. When I lived close to the gulf coast I would put my two canoes under the eves of the house, that water was used to flush the toilet.