Experimental plugin for Neotokyo. Forces alltalk off when the ghost is picked up. Untested.

nt_ghost_no_alltalk.sp

#include <sourcemod>

#pragma semicolon 1
#pragma newdecls required

ConVar sv_alltalk;
bool alltalkWas;

public Plugin myinfo = {
	name = "NT Disable Alltalk When Ghosting",
	description = "Forces alltalk off when the ghost is picked up.",
	author = "Rain",
	version = "0.1.0",
	url = "https://gist.github.com/Rainyan/184816ddbf569a628045b30ed6d339e4"
};

public void OnAllPluginsLoaded()
{
    if (FindConVar("sm_ntghostcap_version") == null)
    {
        char url[] = "https://github.com/softashell/nt-sourcemod-plugins/blob/master/scripting/nt_ghostcap.sp";
        SetFailState("This plugin requires the nt_ghostcap plugin:\n%s", url);
    }
}

public void OnPluginStart()
{
    sv_alltalk = FindConVar("sv_alltalk");
    sv_alltalk.AddChangeHook(AlltalkChanged);
}

public void OnConfigsExecuted()
{
    alltalkWas = sv_alltalk.BoolValue;
}

public void OnGhostPickUp(int client)
{
    alltalkWas = sv_alltalk.BoolValue;
    sv_alltalk.BoolValue = false;
}

public void PushOnGhostDrop(int client)
{
    sv_alltalk.BoolValue = alltalkWas;
}

void AlltalkChanged(ConVar convar, const char[] oldValue, const char[] newValue)
{
    alltalkWas = newValue[0] != 0;
}