If the reason for postponing the football was because they thought Celtic and Liverpool wouldn't respect the protocol, then that is a poor show. If Celtic and Liverpool didn't want to pay their respects then that is up to them. To deny the majority of football supporters to pay their respects then that is lack of respect from the FA.
Little evidence to prove this is a concern of the FA....but an abundance of evidence demonstrating their incompetence and contempt for the public in general.
If this was their concern, they they should be saying so without naming clubs. If they want to be so upfront to mention Liverpool then they could have, followed up by postponing their game and then dealt with the consequences from Liverpool's lawyers and sponsors