And let's consider what this "sanitary changing pod" would require:
It's going to need to be at least as wide as a normal cubicle but probably should be a little wider because some are so narrow moving your arms is almost impossible anyway. So probably can't fit as many as a standard cubicle into the same space so where we would have put 5 toilets we can now put 4 (which, to be clear, is being converted into a toilet and isn't already one!)
It's going to need sanitary bins, that's fine all ladies loos have them anyway
It's going to need toilet roll, again normal. But it's also going to need to go somewhere as there's no toilet to flush it down. The sanitary bin? Well it's going to fill up much quicker that way so will need emptying more. Or something else? Oh that's filling up this space more.
It's still going to need sinks so plumbing with have to happen anyway
It will need some kind of seat, a chair or fold down seat, because whilst they might not all need a wee at the same time, some women will still want to sit down. This takes up more space again, better increase that to a bigger cubicle actually to be effective. We can fit 3 in here now...
Oh but we need to provide something to sanitise that seat. Because someone's vagina and ass have definitely been on there and people are not going to want to sit on that. I mean people are squeamish about loo seats and on those most of the "dirty bits" are actually situated down the "hole" as it were. Plus, as this is specifically for changing sanitary products then there's a good chance there will be blood. Even if they stand up, there may be blood on the floor.... well, we'll need a good supply of wipes. But need to be careful about chemicals because it's just open to the public to use...
Maybe some kind of sluice could be included to flush the floor, a bit like a toilet flush. Well that will required the cubicle being fully enclosed, the plumbing and pipework fitted and probably needs the cubicle to be bigger. It will make 2 cubicles instead...
You know what, we are having to fit plumbing and drainage and sanitary bins and loo roll anyway. Let's build 5 toilet cubicles which any woman can use for any purpose instead...