IG Writing Tablet/Journals are erased when your pack is yanked.

[Ironside]

I'm uncertain why this happens but when you are subdued and your pack is yanked, any of these journals that aren't presently contained in a writing tablet revert to their default, store-bought form.

The one difference is that you can no longer write in them, as if they're still filled.  It's a bit frustrating, to say the least.