Hmm? This calls for a new topic. Iron Tail- A useful & unique move to Pikachu that was introduced in the anime to Pikachu in Generation 3, which has helped Ash/Satoshi win many battles, including gyms, battle frontier, etc and has been held onto all this time through the Kalos region/Gen 6. Also in the anime Pikachu has learned 2 new moves since Gen 3, Volt Tackle in Gen 3 and Electro Ball in Gen 5... so it's worth noting despite Pikachu having learned 2 moves, Iron Tail was one of the moves that was never replaced by any of the new moves he learned previously. Mainstream handheld game series Pikachu was also able to learn this as a TM, just like Skull Bash was teachable to Pikachu as a TM in Gen 1, in Generation 3/R/S/E till Gen 5. Furthermore, PokePark 2 Pikachu also uses Iron Tail as if it was a signature move of Pikachu's. Vs Skull Bash- An (obsolete) TM move, like Iron Tail, in Gen 1 and only Gen 1. Don't have any more positive detail on skull bash but the fact that it's iconic, which though should honestly be less iconic for being milked so hard and non existent to Pikachu's move-set outside the Smash Series for such a long time, specifically 5 Gens and going.
Iron Tail clearly has much more value and relevance to Pikachu than SB. We've had SB for 3 games now, 4 if you count Smash Bros 4 because we already saw a screenshot of Pikachu using SB. What's funny about SB not having been taken out in Brawl is the fact that Brawl came out in 2008, while the first Gen 3 games, Sapphire & Ruby, came out in 2003. This means despite how many yrs Pikachu had Iron Tail learnable by TM in games and the anime as support... with SB being 2 gens old at that time... they still kept SB for some of reason and that reason may have been for it's (stupid) iconic status. But.. now after EVEN MORE yrs have passed by and Iron Tail has became a deeper staple in Pikachu's move set in the anime (indefinitely for the time being) and games (till gen 5) while SB just gets more obsolete, Iron Tail should NO DOUBT replace SB by now - Smash 4. Brawl was already overboard, and IT has earn it's worthy entry as a respective and relevant replacement to SB. AND WHEN IT does finally get incorporated into Pikachu's move-set, it needs to stay in there longer than it originally should due to SB taking it's spot twice - add that up and it equals 2 installment sequels.
I can't believe I've sorta agreed with people in the past to keep SB just because it's ONLY helpful to Pikachu's recovery. That's a terrible & lackluster point when compared to what IT can have the potential to do in Smash 4 and it's status outside Smash. With how much positive weight IT holds, it's a worthy and necessary replacement to SB.