How dare you ask a legitimate question about anything other than job market or Trump...lol
In my group's case it varies because we cover different hospitals that are not affiliated with one another. There is no "standard" per se by the hospital, because that implies there's a person e.g. lab manager or committee who reviews what current facilities and laboratories using regionally/nationally as their respective equipment like they do for other products such as blood analyzer, chem analyzer, etc. Pathologist's microscopes generally don't fall under that umbrella.
Our contract states, "The hospital will provide the necessary equipment for the pathologists to perform their duties". This can certainly be open to interpretation, so I would check to see if your group's contract addresses this. If your equipment is malfunctioning, that's one thing: the hospital must fix or replace it. However, if you're just looking for upgraded microscopy equipment or the latest and greatest gizmo with all the bells and whistles, admin would have to approve it in their budget and their responses can vary from one place to another. For example, we did get a microscope upgrade at one of our hospitals over a year ago fairly easily because the other was ancient and this particular hospital is well off financially. On the other hand, a different hospital we cover has two solid Olympus BX-40 & BX-45's. Not quite 20 yrs. old like yours, but between 5-10 yrs. My colleague would like to get a double headed scope and admin is asking, "Why do you need it if your current scopes are working?", so the idea got scrapped.
Now, we're also trying to link up to telepathology because sometimes pathologists in our group are covering places solo or they can't sign out a case until they make it back to a certain hospital which won't be for another three days, etc. The equipment necessary for this has a better chance to get budget approval because of the benefit of Q/C, TAT, etc. The other option if your group really wants the upgrade in microscopy and the hospital is being stubborn is to pay out of your company/educational fund for which you can probably get a tax break.