Sua sponte court sanctions outlawed by Williams v Pennsylvania?

On June 9, 2016 the U.S. Supreme Court decided a case Williams v Pennsylvania, where, in its holding (not dicta) the court ruled that there is a constitutionally intolerable possibility of judicial bias where a judge is also acting as an accuser.

Williams v Pennsylvania is a majority decision, and thus considered in the American jurisprudence to be a binding precedent on lower courts.

State and federal courts in the U.S. routinely commence proceedings for: 

• sanctions for "frivolous conduct", 
• attorney discipline and/or 
• contempt of court - civil and criminal -  "sua sponte", which means "on the court's own motion".

Yet, when a court commences a proceeding "sua sponte", the court acts as an accuser and prosecutor, and, under Williams v Pennsylvania, as of June 9, 2016, may not remain on the case as an adjudicator.

So, we can see Williams v Pennsylvania as a MAJOR decision undermining judicial power to retaliate for criticism.