Upon logging into the older launcher yesterday i had a pop up stating there was a new launcher, after removing the old launcher (via the steps provided!) and then reinstalling the new launcher, I now have no access to Java, it seems like this may be an ongoing problem with your new launcher but it seems to affect windows versions as well. I have tried clean reinstalls of minecraft as well as the launcher to attempt fixes. However, upon reentry to the launcher, I am only able to see the demo, and it asks me to purchase another copy. 

(picture attached of mojang account with proof of ownership of the game as purchasing is no longer an option, just downloading)