If it's held every year then it's up to the police to state whether they can support a safe environment for these two events and advise the club who will then advise the EFL
I suspect what's happened is that the police have now realised it's a bank holiday weekend and they can't raise enough officers on overtime to police these two events so they,be now told the club they don't have the resources to support the football match
It really is astonishing that this has had to be postponed after travel arrangements have been made and at such short notice.
Incompetent.