probably not.
unless the planet is water all the way down, I don’t think it’s possible to have life or even submerged landmasses that don’t have the chemical elements that can create salts. dead things would dissolve in the water and chemicals in rocks will leach into water over time.
now if this water planet is far enough away from the sun to freeze, sure. the frozen ice should be all fresh. I’m not aware of any salts that stay in frozen water ice. the stuff underneath the frozen stuff most definitely will be salty.
not a chemist or chemistry major but I’m using the word “salts” deliberately. there’s more types of salt than NaCl.
the profanity flies frequently at my place of work. we do give writeups if our employees are saying that in front of customers.
except for me, because I don’t curse (out loud). in fact if I start doing it everyone around me would actually be worried if I was okay.