You kept it... good for you!
There is a work-around for this. (Although I use the phrase work-around loosely).
You can view and annotate in the Metro Reader, however (as you already know), when you save, then reload, it is distorted annotation. The work-around is to open it in Acrobat Reader (Metro Version) to read the annotations and print.
Even though the annotations are distorted in the Reader, you can still reload it in Reader, annotate more, and save again (As long as you use Acrobat Reader to read/print the annotations.).
I know it’s a clumsy solution, but at least you can do everything on the Metro side and don’t have to convert any files first. Hopefully Microsoft will fix it soon.