Cornerstone 3.2.2, x theme 6.2.2
1) for "Add new post" there is no longer an option to edit with Cornerstone
2) for 100 posts that were created with Cornerstone, they no longer have and "edit with Cornerstone" option
3) 3 pages that were created with Cornerstone are still editable with cornerstone
I didn't edit the posts outside of Cornerstone as that volume of posts is something I would remember doing.