I was notified not too long ago that they were going to be getting rid of the property management company they were working with. This is only a month after I started renting.
I like property management companies because I don't have to deal with these type of people that I despise as well they offer SLAs/ticketing systems, in house maintenance, fast response time, after hours emergency numbers, etc, etc.
I checked here: https://www.ontario.ca/laws/statute/06r17#BK193 and it says that I can get a rent decrease if there is a removal of a service so I'm going to make sure they don't forget that and if they say no I'm going to the tenant board.
Have you called the LTB to see if they consider removal of a property management company a "removal of a service"?
My hunch is that it'll be an uphill battle for you at best. The landlords will have a reasonable case that they are simply changing service providers from a company to themselves, and as long as the property is still maintained and repaired in a time frame that is compliant with the RTA, my hunch is that you don't have a case.
Do keep us updated, though.
One could argue the ticketing system and the 24/7 emergency numbers are services being lost.
Interesting to see LTB take on it though.