Yes! It also shows how the Senate hearing highlights the Fifth Amendment as a two-edged sword:
Criminal defendents are not required to be sworn in and take the stand against their will. Most juries don't hold it against them that they didn't testify on their own behalf--they've seen all the lawyer movies and TV shows, and they know how a prosecutor can rip a witness to shreds. Criminal defendents are almost never hurt by refusing to take the stand.
But a witness before a Congressional hearing can't refuse to be sworn in--he must take the stand. His Fifth Amendment privilege extends only to being able to refuse to answer specific questions "on the grounds that my answer might tend to incriminate me." In Michael Corleone's case, a Senator asked him if he was "responsible for the murders of the heads of the Five Families in 1950 [sic]." Suppose he replied, "I refuse to answer that quesition on the grounds that my answer might tend to incriminate me"? He couldn't be prosecuted for perjury or for the actual crime--but everyone on the planet would know that the reason that his answer "might tend to incriminate me" was because he was responsible for those murders.

Real-life Dons have a nominal "legitimate" job whose purpose is not to make them appear to be solid citizens, but simply to provide them with a source of reportable income so they can avoid being prosecuted for tax evasion. If they're called before a Congressional committee, their lawyers will advise, "Look, our purpose here is to keep you from being jailed, not to convince your fellow citizens that you're an honest businessman. Just plead the Fifth after every question." If the Don were to say, "But if I did that, everyone will know I'm a gangster," the lawyer would reply, "They already know you're a gangster--better to be a known gangster at liberty than a known gangster in jail."
Of course, Michael was pretending to be a genuinely "legitimate businessman," so pleading the Fifth would have destroyed his credibility.