New York City landlords, developers, and real estate investors would gain if lower rates emerge from a planned overhaul of the city property tax system, but renters might not see long-term benefits.

That was among the takeaways from a panel of experts testifying Jan. 22 before the New York City Advisory Commission on Property Tax Reform, which is charged with recommending revenue-neutral changes to improve the fairness and transparency of the widely criticized system.

The commission, created in the...