CantHideStaff is a very simple plugin that prevents normal players from hiding staff chat messages using the social interactions screen added in 1.16.4.
Any messages that use the default format will still be hidden, to prevent this you must use a chat plugin.

Give players the canthidestaff.staff permission to allow their messages to be shown.

There are two modes: broadcast and packet.
To choose between them change the packet setting in the config file.

Default config:
Bypassing will only work if players have "Hide Matched Names" off in chat settings.
Packet mode requires ProtocolLib.
This plugin is meant for staff use only, please don't use it as a way to harass other players.