Kevin Nash broke kayfabe in Madison Square Garden and lead WCW to a year run that nearly put WWE out of business - He came back
Hulk Hogan - Left Vince in the wake of the Steroid Trial and became the face of his biggest business rival - Add in his son's vehicular homicide, his messy divorce and sex tape, and management position with TNA and yet he is back
Brett Hart - Enough Said
Bruno Sammartino - Ditto
Ultimate Warrior - he didn't even deserve to come back, and yet....
Steve Austin walked out on the company more than once - add in his outspoken critiques of WWE at times in public and his multiple domestic violence arrests and yet....
The Rock's movies career....and yet.....
Kurt Angle almost certainly will come back - It will depend on the deal and what both sides want (Hogan wanted more money and in ring role and he didn't get it, eventually the two sides settled and he's back) - But yes, unless Angle absolutely doesn't want to return he'll be back.