I have to agree with G on this, the findings of the accident investigation will have to focus more on the airshow environment rather than the participating aircraft. Yes, the energy management, and possible trajectory of the aircraft will remain focal points, but no matter how hard one tries, it is not possible to assure that a plane is going to go where intended. The only certain thing to protect "the public" is to assure that the path intended or potential is clear of "innocents".
This will result in an increased burden upon airshow organizers to present an operational plan which considers a broader scope of unintended outcomes, and mitigation. The regulator will not want the task of "designing" the safe environment, only "approving" of a proposal when compliant. I expect that the AAIB will be making recommendations as to what changes would be appropriate to the environment in general, and the CAA will eagerly await those findings so it appears that are being proactive.