Logical error for disabled users

Description:

earlier, when I deactivated a user in the admin panel, the chat channel with him became read-only.
now I can continue chat with the deactivated user.
how to return early behavior?
it is absolutely logical that after disabling the user, the room (DM) with him for all users becomes read-only status, which helps users to understand that this user has been blocked (in our case, the user was fired). Also, switching the channel to read-only status helps not to clog the system further if someone mistakenly writes to the wrong user.

Steps to reproduce:

1. Go to admin panel
2. Disable user
3. Still can write to him. DM with him NOT in read only status

Expected behavior:

After disabling user i expect the room with him set automaticaly in read only status

Actual behavior:

After disabling user, i still can wrote to him

Server Setup Information:

• Version of Rocket.Chat Server: 3.12.1
• Operating System: Ubuntu 18.04
• Deployment Method: tar
• Number of Running Instances: 1
• DB Replicaset Oplog: Enabled
• NodeJS Version: 12.18.4
• MongoDB Version:4.0.12

Start by tracing the admin-panel user deactivation flow and the permission checks that govern writing to direct-message rooms. Reproduce the issue with a disabled user, then verify that the affected room becomes read-only for all users without preventing unrelated conversations.