Keep in mind that a lot of these physical exams, whether it's for a fire department or a box-carrying job, typically have little to do with the actual demands of the job. Keep in mind I'm not making any such assertion with this case, I know next to nothing about the fire department physical exam for FDNY. It could be perfectly representative of the job demands, in which case this would not be okay. It's not okay either way, really.
However, these types of exams usually conform to some sort of average of people they want to accept any given year. If they see that less people are passing the physical exams, then they will naturally lower the standards, even if it's for the year. They still need workers after all, and there's both a ceiling and a floor for the number of people they let in. And naturally, they want the best-conditioned people they can get without excluding people.
So one still needs to take a look at the test and decide whether or not it is truly representative of the work that will need to be done, or just a way of ranking prospects' physical capabilities with no real regard to occupational relevancy.
All of that being said, it's not exactly ideal. Countless women are trying to prove that they can do these things without special treatment, and it is a bit of a slap in the face to them. The fact is that girls aren't exactly taught that being a firefighter or soldier or anything in that ballpark is really available to them as a career choice, so as a result there is no surprise when there's barely any women trying out, let alone actually making it. That is the problem that needs to be addressed, not just trying to reconfigure exam standards.