Alert notificaton before Publishing an extension

Dears,

I trying to find a way to notify the users that I’m going to publish an extension, because it will kick them out the system when i publish it.

If anyone got any idea doing it let me know.

Example of what I’m saying:

Before I publish the extension an alert box appears to all the client users that the extension will be published so they save their work and close the software.

Thanks in advance