Time to throw in some controversy.
Do you think the Blunderbuss may actually not make an appearance? Do you think some irrational folks up at Nintendo may think that the blunderbuss is inappropriate because "guns are bad?"
You would think that such a think would be foolish. After all, the Blunderbuss itself is very cartoony, and from what I remember from DKC 2, it was used as a vacuum, shot out various gases, and shot out cannon balls (classic cartoon artillery), not real bullets.
Yet, as much as I want to say "LOL! That's ridiculous!" I can't underestimate the power of nazi censorship for Nintendo's "kid-friendly" audience (not just Nintendo, but just media in general, uptight about every little thing). Doesn't help the fact that besides the ray gun, or Fox/Falco/Wolf's blaster, K. Rool's blunderbuss is much more reminiscent of a real gun.
I think such a scenario is insulting dumb, but at the same time, I honestly wouldn't be surprised if something that dumb actually happened.
While I disagree with your reasoning as to why a Kremling Toss couldn't work, I
do like the reasoning that K. Rool, despite the tricks up his sleeve, generally fights the Kong's alone without having to rely on his subordinates. Thus, in Smash, I can get behind him not using any Kremlings (with that said, I do want Klap-traps to appear
somewhere...anywhere. Maybe a stage hazard or assist trophy?)