Sure, Fan and Pipe are essential when it comes to Hidden Masteries but I think many are missing the point when there's talk of a Leaf exclusive weapon. The issue doesn't lie in Leaf being in need of a village-only weapon (although it would be nice to have Chakra Blades, and I believe @Spooks already made a post regarding this topic with some Leaf villagers doing pixel art for the Blades), but rather that Fan and Pipe are available to all in their respective villages and the very fact that they can be used by everyone does not only break RP (e.g. how can ninja who didn't master Wind / Water release wield a fan or use a pipe?) but also puts Leaf shinobi at a disadvantage when fighting Sand or Mist (e.g. cancel ability of Fans / Mist elementals relying on bubble-snare combos) which makes fighting these villages frustrating to say the least due to the abundance of Fan / Pipe users.
If one were to even the field, they'd have to (and this has been stated and ignored countless times before) lock Fan and Pipe to their Hidden Masteries. This would not only balance PvP but also restore RP as it would decrease the number of people using hidden weapons without the proper chakra nature and prevent the abuse of Fan / Pipe perks in combat.
Regarding the Specialty Weapons: Adding these weapons into the game wouldn't really solve anything as long as Pipe and Fan are not locked to their respective masteries, since it would not change the status-quo at all. Sand would now have Fans and the Gourd, Mist would still abuse the Pipe and get a Kusarigama to boot and Leaf would get the long-awaited Chakra blades only to realize that nothing changed and the disadvantage in PvP remains the same.
Bottom line is: If Chakra Blades were to be added without locking Pipe / Fan to their masteries it would only be fair that Leaf receives them without Sand and Mist getting upgrades due to the aforementioned reasons.