They definitely want to. Old Reddit is simple, efficient, and mostly free of the obnoxious limitations and extra 'features' found on the new design. It's the exact opposite to what a company pushing a mobile app wants to see.

But they're in an interesting situation where they can't really get rid of it, because many of the site's power users are using it. Subreddit moderators use it for tools that aren't available in the new interface, regular submitters have kept using it for decades, etc.

So, they're kinda stuck. They want to kill it, realise that doing so would be a terrible PR move, and are hence trying desperately to 'encourage' said existing users to move over or leave.