Then I can certainly see how police have created this problem for themselves, in Edmonton and in Toronto.
If you're in uniform, being paid, on duty ... then you are not just participating in the parade. So stand aside and monitor for any problems, like police always do at parades.
If you're an off duty officer and just participating in the parade for personal reasons, don't wear a uniform.
You can't have it both ways.
You can't pretend to be participants when you're really on duty policing the participants.
BLM was right.
Sure they can, why should they hide what they are? Pride organizers don't dictate to other groups what they can wear.