Our R&D team is working on a feature for Chatter that would show that a message was edited, and provide a way to see the history of the changes made. 

We are targeting this for the Odoo 18 release - note that we frequently delay, modify the scope of or cancel entirely planned future features - so you should never rely on any statements we make about unreleased features.

Hi,

Refer to the below link, it shows how to remove the edit and create button in odoo15
https://www.youtube.com/watch?v=-gNrjyvurD8

Hope it helps you