This can only be tested on multiplayer or if you open singleplayer to LAN, because the game pauses when opening a book in non-LAN singleplayer.

When you open a written book, and the book is then modified, or the book deleted, the gui isn't updated nor closed.

Steps to reproduce:

1. Make a small command block setup as shown in the image
   First command block (with button) has the command

   item replace entity @p hotbar.0 with minecraft:written_book{title:"Test Book",author:"You",pages:['{"text":"Test","clickEvent":{"action":"run_command","value":"/say hi"}}']}

   The second command block has

   item replace entity @p hotbar.0 with minecraft:written_book{title:"Test Book",author:"You",pages:['{"text":"Changed book"}']}

2. Press the button
3. Open the book in your hotbar before the second command block is powered
4. Wait for the second command block to run
5. Observe how the hand indicated the item changed, but the gui didn't update.
6. Click the text
7. Observe how the say command runs, while the player should no longer having access to it.

Replace the second command with

clear @p minecraft:written_book

And repeat steps 2 and after; notice the same result, even with the book gone that the gui doesn't disappear.