Does anyone think that software developers should be prohibited by law from looking at what other software developers are charging before deciding how much money to ask for? I don't believe that. Why would it be illegal for landlords to do it?
The article shows no evidence of price fixing. It shows companies doing absolutely normal things that every company does in order to determine what price to charge. Yes, that means looking at what other companies charge for the same service. Yes, for landlords it sometimes makes sense to accept a higher vacancy rate in exchange for higher rents. Sometimes it would also make sense to accept a lower vacancy rate in exchange for lower rents. Yes, landlords are going to want to look at market data to determine what the vacancy rate is that makes them the most money.