The past Production team should be the one to blame. I forgot what's the Production Group name but they have a Commercial where they are Making WWE "Safe for the Environment" thing
They stopped using pyro in mid-2017 on a full time basis due to financial problems, until they started using pyro on a full time basis again in September 2019.
+DekuLevi 93 That would’ve been one of the reasons. When handling pyrotechnics, only they can be used by highly trained professionals. Plus, they can cause a fire hazard.