Kamui and Baluski were right this topic is pretty old and the event was taken out. Very much like,"The Day the Sky Rained Blood", "Santa Neji", and "Pirate Day". Particular events can only last for so long. Konohamaru can't be around forever, like other aforementioned events it might be brought back at a certain time or junction of the year. Having Konohamaru stay year around is like having the 'The Day the Sky Rained Blood' year around. Plus, it wouldn't make much sense to have both Konohamaru and Shinobazu all year long.