Universal workaround for usage in a preInit function:

{
	_x params [["_chan",-1,[0]], ["_noText","true",[""]], ["_noVoice","true",[""]]];
	_chan enableChannel [(_noText != "true"), (_noVoice != "true")];
} forEach getArray (missionConfigFile >> "disableChannels");

This issue persists in version 1.62.137306 RC (30-06-2016).

This issue still persists in version 1.64.138310 RC (09-09-2016).

I will emphasise that this issue will only occur if the player aborts to the role selection screen/lobby and then rejoins. The issue will not occur they fully disconnect from the server and then reconnect.

This issue continues to persist in version 1.64.138425 RC (17-09-2016).

This issue still continues to persist in version 1.66.139279 RC1 (11-11-2016). Come on, guys.

This is still an issue in version 1.68.140908.

disableChannels settings cease to work when leaving/rejoining mission in version 1.76.142872.

big problem !

Is this fixed or still a problem? :|

I hope someone will fix this in the encore update

oh guys i guess its still not fixed?

should be fixed in 1.99.146546

Still not fixed.
Sometimes it works, sometimes doesn't, you even don't need to go back to lobby, and rejoin a mission.

In T117205#2399176, @Schatten wrote:

Still not fixed.
Sometimes it works, sometimes doesn't, you even don't need to go back to lobby, and rejoin a mission.

Sorry this is not helpful, please provide steps to preproduce the mulfunction

In T117205#2399405, @BIS_fnc_KK wrote:

In T117205#2399176, @Schatten wrote:

Still not fixed.
Sometimes it works, sometimes doesn't, you even don't need to go back to lobby, and rejoin a mission.

Sorry this is not helpful, please provide steps to preproduce the mulfunction

Unfortunately, I can't provide a list of concrete steps to reproduce this bug. The only info I can provide is that I have a dedicated server with this piece of code in Description.ext:

disableChannels[] = {
    {
        0, // global
        false, // enable text
        true // disable voice
    }
};

And despite this, when I join to the server VoN is sometimes available through global channel.

The global channel is never disabled for admin or server host could you provide the steps to reproduce please

Thanks for the explanation! Probably I was wrong, at least I couldn't reproduce this "bug" by launching a dedicated server on my local PC and connecting to/disconnecting from it many times. I'll keep watching and let you know if I can reproduce it.

Well, after a week of testing I couldn't reproduce this "bug". Seems I was confused by the fact that when I logged in as admin global channel was available.
Again, thanks for the explanation, @BIS_fnc_KK (makes sense to update BIKI), and sorry for the false alarm.