I calculated the number of units owned by real estate investment trusts per province and then compared that to the national share of apartment units in that province to see if they owned more than what you would expect, given the share of apartments in that province. I found that provinces that had stronger rent control had lower proportion of REIT ownership compared to what you would expect, and provinces with weaker rent control were the opposite.
The indication there was that rent control can play a role in reducing the financialization of housing or, indeed, can play a role in preventing firms from wanting to acquire properties in those jurisdictions.
With reference to your question about anecdotal evidence, it's also the case that these firms make it very clear that they are not in favour of rent control. You can read their documents, and you can listen to comments that REIT executives make. They're all very opposed to rent control of any form.