No ur good. Whirlfloc deals mostly with the coagulation of proteins for the cold and hot break. It allows these proteins to coagulate together, basically becoming bigger/heavier and dropping to the bottom. Not using whirlfloc or irish moss will keep more of these proteins suspended in the wort, which can lead to hazy beer. Yes it can drop into trub in the kettle but it can also occurr in ur fermentation vessel so in theory u can still dump everything from ur kettle into ur fermentor and still see a difference when using whirlfloc/irish moss.
This is a link i bookmarked a few months back when i was throwing around the idea of using a tablet. every batch i make that isn't a wheat beer or belgian gets a tab. Yooper knows her **** and she posts some good scientific stuff on how it works.
https://www.homebrewtalk.com/f37/whirlfloc-extract-192043/
Something else u can consider depending on your BK, is a diptube. U can cant the tube at a slight angle, make a whirlpool and alot of the hops particulars and any strain grains and other material will "dome" in the center of ur BK, while the diptube sucks out all the wort from alongside it. I am fine tunning my dip tube angle on my new keggle and its nice because alot of the stuff gets left in the BK for easy rinsing while all the good stuff gets into the fermentor.