Well...yes.
LGBT groups have their own racial issues, that are being addressed now. There are clear reasons why black GBT groups do not want to appear alongside police groups - mostly relating to brutality and sexual assault - and since these police are being openly invited over the strong objections of black LGBT groups, well...
The police in Toronto have a bad history with LGBT folks, and have come a long way. The police marching alongside the LGBT people in the parade is an explicit statement that the police policy is to stand in support and be inclusive of the LGBT community. The vast majority of LGBT people support this.
Why should BLM be allowed to BAN the police from marching, fo against the will of the majority and hijack the parade for their own cause?
I wonder how people would react if the roles were all reversed.
What if the government banned Muslims from participation in black history month despite most blacks wanting wide support, because some gay black people objected to Islam's bigotry towards homosexuality?
For that matter, what if Trump banned Muslims from entering the USA because some of them are dangerous bad people so some Americans oppose them being there? You know, despite that most of them aren't. Isn't that similar to BLM wanting police banned from marching in the parade? Most of them aren't abusive towards blacks, right?