I've never heard of or been made aware of any fleece treatments for liners and I've made them for almost three years now, so I would say you are safe to wash it in a fragrance free detergent and put it in the cage. Remember not to use dryer sheets or fabric softener though.
Congrats on your new little one!
It wasn't exactly a treatment... More like a specific way of washing the fleece so that all the liquids go right through to the absorbent material underneath. Thanks for all the help. I think I was getting a little worried about nothing.
And thanks. I'm really excited about getting her. Months of research and learning all leading up to getting her. I'm sure it'll be worth it, even if she is the little grouch she looks like in the one picture I've seen.