Is advising your client that there is a legal requirement that they should discuss with a lawyer, in itself the unauthorized practice of law? 

Filling out tax returns is obviously the practice of law, but there aren't enough lawyers around to do it so every unlicensed preparer, from H&R Block part-timers on down are allowed to do it. I fail to see how helping someone fill out a form with ownership information is anything more than helping someone fill out a form with ownership information.  If a question arises as to the correct answer, you can always refuse to finish

Are the instructors at driving schools practicing law when they advise students on how to comply with rules of the road?  Are gun dealers practicing law when they help customers get past background checks? Playing the UPL card may be one way to lobby for repeal, but I wouldn't take it too seriously.  It will be interesting to see how many CPA's who are washing their hands of participation, will lose clients to those who are willing to help (for a fee).  What I suspect is that a cottage industry will pop up, with enterprises that do nothing but FinCEN compliance.  Until they add other services, like tax return preparation.