Would a co-op board's removal of half the dryers in a building's laundry room be a reduction in services (about half of 60-unit buildings units still rent-stabilized.)
Removing half of the dryers seems like a reduction in services to me, particularly if you can show a negative effect, such as longer waits to use the remaining machines. It may also be a prohibited discrimination against the rental tenants if the co-op allows shareholders to install their own washers and dryers, but regulated rental tenants do not have the same rights.
It costs nothing to fill out the DHCR reduction in services form. The regulated tenants should actively insure that their rights are being protected and that everyone on the co-op board and management knows that there will be a price to pay when changes are made without consulting the regulated tenants.