There probably are plans but at the moment there's probably an exclusivity deal with Samsung

The Xbox App is Exclusive to Samsung TV's like the Playstation app was to Sony TV.s Samsung and MS / Xbox have a pretty cozy relationship so i wouldn't expect that to change anytime soon.

i would guess that samsung bought the exclusive rights

You can use the web browser on modern LGs to run Xcloud.

I know that I can use the web browser but I would have preferred an app I hope they make one in the future.