"The guilty plea of Bo Han Song is one more step in a long road of towards justice for the parents of Tim Piazza."
Twenty other defendants still face charges in the case. A trial for most of them is scheduled for February 2019.
The one-hour and two-hour restrictions also will not be enforced beginning at noon on Friday until Tuesday morning.
A preliminary hearing is scheduled for Wednesday.
Seven former Beta Theta Pi brothers were back in court on Tuesday for another preliminary hearing in the Penn State fraternity hazing case stemming from the 2017 death of pledge Timothy Piazza.
Penn State police confirmed the tweet being investigated was sent on Wednesday night from a since-deleted account.