After a little research....
Really, the only thing that happened was that Co Yaw Yaw was smart enough to realize the incredible amount of talent they had was being wasted in the prehistoric offenses LSU had been running since the beginning of time. After they got shut out by Bama, he openly said we're going to the spread. They went and hired Joe Brady, a 29 year old who was a lowly assistant with the Saints. He had played WR at William & Mary, I believe. Brady learned his offense from Joe Moorehead while an assistant at Sandusky U, then added some aspects of Sean Payton's attack at N.O.
Having said that, Steve Ensminger remains the OC and QB's Coach. Brady showed them the offense and coaches wide receivers. Did either of them turn Burrow into a truly transformed, NFL ready QB, with awesome footwork and the sudden ability to work through progressions? Ensminger? Really? Brady? He doesn't coach QB's. Or did they simply give Burrow the ammunition he needed to show what he already had the capability of doing? Remember, he spent 2 years learning in a wide open offense at tOSU. Doesn't everyone accuse Malzahn of not being able to have success at the position unless they trained elsewhere?
LSU has a massive and talented O-line, bad ass running backs and an assload of 4* and 5* receivers. They've had that for as long as I can remember. Orgeron finally realized (As K has stated) the obvious and turned all that talent loose.