Xbox needs to fix this problem with no way to add disc to digital version

As of today any play anywhere game is only available if you have the digital version of the game. If dont even work for disc versions of xbox one games. So i guess this will not happen. On the digital versions there is no problem to check with your account
that you have bought the license of the game. That is not possible for a disc version. So maybe they will add digital xbox 360 games to that cataloge.

You would only need to do this if you purchase the All digital Xbox One S that has no disc drive. If you purchase an Xbox One S or X with a disc drive they can still be used there. But there is no way to convert disc games to digital versions.

Is there any way for me to exchange the games from disc to digital?

If they cost the same price, could I not bring the disc somewhere and be able to swap it out for a digital version of the game?

You would only need to do this if you purchase the All digital Xbox One S that has no disc drive. If you purchase an Xbox One S or X with a disc drive they can still be used there. But there is no way to convert disc games to digital versions.

The only way to play a game without a Disc is to buy the digital version. Otherwise you will need the Disc as proof of ownership to launch and play the game.

Just to add that to 'Play Anywhere' requires the digital download version. It does't matter if you buy it from the Windows Store or Xbox, you'll get both versions.

If you purchased the game on disc, you'll need to buy again for PC.