This is how you can fix it, before MS delivers the right solution:

After the package is migrated you find in the XML-Code following part

<DTS:DesignTimeProperties><![CDATA[<?xml version="1.0"?>

<!--This CDATA section contains the layout information of the package. The section includes information such as (x,y) coordinates, width, and height.-->

<!--If you manually edit this section and make a mistake, you can delete it. -->

<!--The package will still be able to load normally but the previous layout information will be lost and the designer will automatically re-arrange the elements on the design surface.-->

<Objects

Version="sql11">

You will have to change manually to following:

<Objects

Version="sql12">

when you open the package after the change then the apperance and annotations will be shown again.

I do not know if this is a Migration Wizard bug, that does not elevate the Version to sql12 or if it is a SSIS-Plugin-Bug, that does not handle the entry sql11 right. This depence on how Microsoft wanted to design it.