Sure seems like it would, because your creating head pressure on the line, the deeper the line the more the reverse effect you will get from that head pressure, which would be pushing back on any beneficial vacuum created thereby reducing vacuum.

Do you have a gauge at the top of the line. Try putting the line in the bottom of the tank. Check your gauge, then have your line drip into the top of the tank and check your gauge again. It may not be detectable on the gauge however... not sure.

I sense that doing this with a drop into the bottom of a bucket will cause problems, both in hydro dynamics and sanitation.
Sanitation for certain a problem here.

Higher then atmospheric pressure is pushed back towards any column of sap generating vacuum or the tap hole itself if no column/vacuum exists (i.e. drops to buckets )