What they're effectively saying is that "Services that estimate rent prices should be illegal."
OK. Good luck with that.
In most markets when a single participant defects from a cartel they can flood the market.
When 70% or housing is under control of a single pice of software the other 30% can’t flood the market.
If there were 50 of these companies all competing in a particular city it wouldn't be a problem, but when most apartments are priced by just one or two companies, it is.
I am strongly on the side of: yes, they can.
In a time where most offerings are public you just need to make sure you stay slightly above the p50 and prices will go up.
Similarly on the buying side of e.g. Ads most algorithms and platforms have a "bidding war avoidance". Stop bidding more even of it would make you money, in order to keep the proce low.
In all those cases you try to sync and rise /lower the price (as seller/buyer).
It's not about just estimating a price. It is doing that on a large scale with an algorithmic outcome of upwards price fixation.