I'm totally fine with AC not ever being remade. As an animation it's barely showing its age even now, and the blueness was iconic. The film wasn't deep and doesn't stand alone narratively so well, but everything was still iconic as is to fans, so I think it's best to leave it in 2005/2009.
As for OWTAS: I was recently thinking about how badly I want to see it in CGI. The books in general, but especially OWTAS. I don't think it'd work as DLC, so I think it would be best sold as a mini series.