Sedition is merely inciting a rebellion against an authority. Their actions were certainly rebellious in my opinion and you can call them seditionists all you want, I have no problem with that.

A coup on the other hand, is overthrowing the government and something these people had zero chance of doing. (or 1:limx→∞ (1/x) at best)

I can make this argument due to the implausibility of the alleged objective.

Notably, to disrupt the "peaceful transfer of power" they would have needed to attack the executive branch of the government, not the legislative branch.