Not really. Mickey and Riku-Ansem both had their own Keyblades in KH1 and King Triton implied there was at least another Keyblade wielder as he had knowledge of it beforehand, implying others exist. The Keyblade was never really a "only one" weapon when you really think about it. It's just they were rare to come across at the time of KH1 because the other wielders either were sealed away somewhere or weren't born yet.
Yeah, people miss this when talking about the uniqueness of Keyblades. Sora's considered the "chosen one", but even in KH1 they walk that back and say Riku actually was the true chosen one. Triton especially is overlooked because it was never touched upon again. Sora just mattered a whole lot because he was the one who had the Kingdom Key and Mickey needed the Kingdom Key D for what they needed to do.
And if two people could wield the same Keyblade at the same time even as far back as KH1, then it shows right there that being a wielder may not be "common" (and it still isn't in the grand scheme of things), but others with the power do exist. And since the KH1 secret ending "Another Side, Another Story" exists, even though that was made without knowing if Kingdom Hearts would spawn into a series (thank God it did), it still shows that somebody other than Sora has TWO Keyblades. So even then, it was never really all THAT exclusive.
While I also like the specialness of the keyblade in KH1 and how magical it felt, I'm not as sad as others that they kinda dropped that. The keyblade as a unique weapon felt like the typical chosen one with chosen one's unique magical supersword trope which is by no means bad, but giving other people keyblades undermined the point of Sora not being the chosen one later. In later entries, especially DDD, they put more emphasis on Sora not being special per se - he's neither especially strong, smart or has great genes - but he has an ability to connect to people that stems from him being a truly sweet guy and that is his speciality.
And that's why I think it worked out for the best. The series since the very beginning has always said that Sora isn't special -- but it means jackshit either way because most of the "special" people chosen by "fate" or whatever you want to call it have to end up being saved by Sora anyway. Riku's the chosen one, yet Sora's out here doing everything. It's the kid you wouldn't expect to be the hero that's the one fixing everything.
If anything, I'd say being chosen is almost a curse.
Now they could have given out new weapons starting with BBS, but really what would be the difference? They'll be doing the same thing as a Keyblade anyway. Slaying Heartless, sending them to Kingdom Hearts to increase it's size. Opening portals and pathways. Sealing up keyholes. Kingdom Hearts follows a formula so even if they made new weapons they'd all just be Keyblades under a different name/look anyway. The series depends on magic Keyblades.
Exactly. Unless you do a complete change-up of everything where Heartless aren't a factor, and you'd still go to different worlds for some reason... But tied into what Kingdom Hearts is all about overall. I mean, this COULD be what Verum Rex might turn into if it's an actual game. Never know.
But for every KH game, you're gonna need a Keyblade present and it's most likely gonna have to be via the protagonist.
My only problem with this is that she'll be overpowered. If she was anything other than kind, all the main players would be her puppet slaves right now. This includes the Disney characters.
Kairi should be OP, considering her Princess of Heart powers, so it's not a surprise Namine would also be OP as well. If Kairi had the same amount of experience as Sora and Riku did, she'd eat everybody's lunch with how strong she'd be.