B61, the CAE Gatwick site is not new, it has been around for quite some time, I did a sim assessment there in 2014, so it has been around for a while, not sure exactly when it opened.
But as I understand CAE Gatwick housed the mainstream Airline sims (B737, B767, assumed it may have A320 sims due to the Easy MPL course but not sure on that), where as Burgess Hill mainly concentrated on Sims for Bizjet types. However I believe Burgess Hill may also have Airbus sims as well.