My answer is, No. I don't think word will trickle down to enough people. There will probably always be a perception among some people that becoming a lawyer will guarantee you an at least solid middle class quality of life and offer an excellent chance of attaining an upper middle class income, at least amongst enough people to fill the law schools.
Perhaps students from middle class and upper middle class families will get the message from their sisters, brothers, and cousins, but legions of students from poor and minority families who think that just gaining admission to a for-profit college is a huge achievement will continue to believe that going to law school is a golden ticket (just as they think that higher education in general and especially graduate degrees will guarantee a ride on the gravy train). If the students from middle class and upper middle class families stop coming, the law schools will simply lower their admissions standards rather than deprive themselves of tasty tuition dollars, and students from lower class backgrounds will eagerly break down the doors, starry-eyed and giddy at the thought that they could become the first lawyer or professional in their families.
Our society has been indoctrinating people about the value of higher education for decades and people from poor and minority backgrounds are especially susceptible to that message because they often don't have any family members who can tell them otherwise. As evidence, I cite the hordes of people who have no business going to college who are flooding into the community colleges and for-profit schools. This notion that higher education is a guarantor of at least a solid middle class lifestyle is deeply, deeply entrenched in the American psyche and exactly zero voices are saying otherwise on a public scale. (Little guys like you and me who gripe on blogs and specialized forums don't count. I want to see Oprah or the President or Brian Williams spread the message.)
Read this article about "Professor X" who teaches at a "College of Last Resort" to get a better sense of what I'm talking about. Hordes of people, including people who have no business going to college, feel desperate to go, believing that higher education will give them a golden ticket on the gravy train. Also watch the Frontline program College, Inc. and read the New York Times article about how well-intentioned people are being suckered into for-profit college debt.
Thus, even if a great many undergraduates learn the truth, a great many will still continue to succumb to the propaganda put out by the ABA, NALP, the LSAC, the law schools, Hollywood, politicians, pundits, and society in general.