Looks like they're just moving it to the Windows store. Yay!
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwi1tJXHgqrVAhVhjFQKHQo2A7sQqUMINjAA&url=https%3A%2F%2Fblogs.windows.com%2Fwindowsexperience%2F2017%2F07%2F24%2Fms-paint-stay%2F&usg=AFQjCNGyg0Z1QA6-c5enxU0VMi1GY8Us0Q
Yay, Indeed!
Good to know - lol.