Yes, if you drop the hops in without a muslin bag or herb ball or something to contain them, they WILL plug your pick up tube, (or more likely, your poppet).
If you put them in a muslin bag, (maybe with a marble or SS hose clamp for weight), then you will be fine.
I know this, cuz I did this. I had to siphon the beer out, and it had already been carbonated. Lost 1 gallon. Sad day.