Not likely.
Per this post, the Plex team has committed to maintain the app as-is, only to fix bugs. There has been no commitment to add new features to PMP.
Based on Elan’s second and third point, I think the long term goal is to make the new desktop app as capable as PMP. However, since they are building up their own player (a branch of mpv) for a more uniform playback experience across platforms, it could take a little while to get to the same capability as PMP.
If you want features, get the new desktop app. If you want robust playback, stick with PMP for now.
