Monster Hunter Wilds won't add a 15th main weapon but the devs talk about one all the time – one problem is the 14 weapons we have are a hard act to follow

gamesradar.com:

The mainline Monster Hunter games haven't added a new weapon type since the introduction of charge blade and insect glaive in Monster Hunter 4 in 2013, and Monster Hunter Wilds won't be changing that when it launches February 28, 2025. However, Wilds executive art director Kaname Fujioka and series producer Ryozo Tsujimoto say the development team talks about new weapon ideas regularly.

Speaking with Italian site Multiplayer.it (machine translated via Google and DeepL for this article), Fujioka affirms that the idea of adding a 15th main weapon was never abandoned, and as a result, a lot of potential ideas have piled up. The important context here is that Monster Hunter technically has 18 weapons, it's just that the tonfa, magnet spike, and accel axe have only appeared in a few spin-off games, while the hilariously named medium bowgun was only seen in Monster Hunter 3.  

Monster Hunter Wilds continues the approach of games like Monster Hunter Rise and Monster Hunter World, Fujioka adds, by refining the 14 existing weapons and taking them in new directions with added moves and features. Wilds, in particular, has given most if not all weapons some sort of counterattack or perfect-timing mechanic. 

Tsujimoto says that matching the level of depth and care in current weapons makes it that much harder to choose and flesh out a 15th. He points back to the charge blade and insect glaive, which have evolved dramatically since their release despite being the newest of the bunch. Classics like the greatsword and longsword, meanwhile, are almost unrecognizable compared to their primitive counterparts. 

It's also a question of development priorities, Tsujimoto notes. Even if the team had a solid idea and also had the resources available to make a 15th weapon, Tsujimoto says they have to ask whether that's actually the best use of those resources, or if the series and its fans would be better served by investing them elsewhere – again, perhaps by improving the current weapons