Silicon Knights: Point. I'll give you that one.
Camelot: Their parent company is Nintendo, who took them from Sega back in 1999. They've programmed exclusively for Nintendo and are even the creators of Waluigi. Thankfully, since they made the Golden Sun series, I can forgive them for that. Link.
Monolith Soft: Monolith Soft was formerly owned by Namco, who sold all 96% of their shares to Nintendo, meaning Monolith Soft is wholly owned by Nintendo and thus for all intents and purposes considered first-party. Link.
Tri-Crescendo: Their developed titles are almost exclusively Nintendo, though you have somewhat of a point since they've done work for other consoles.
Are you going to tell me that Metroid Prime and Donkey Kong Country returns aren't first party because they were developed by Nintendo's Retro studios? As far as I'm concerned if Nintendo owns the studio, it's first party. Beyond that, the original poster suggested that they hadn't done anything new in the past 30 or so years- which is an obvious falsehood since 30 years ago is when the original Mario Bros came out in the arcade. So, unless the poster was receiving arcade cabinets for Christmas...
Not to mention of course all the innovation done within its more well known titles, even if the stories themselves are often "rehashes", they've kept the gameplay fresh.