Is there even a general consensus on what should be done, or is it more of a case by case/funding decision?

I've noticed that it seems that countries outside of the US (at least Western Europe) are more likely to exhume bodies rather than just let them be.

I don't have a large sample size to prove this, but for example I was watching one documentary where researchers in the UK exhumed a mass grave of plague victims from a cemetery near the Tower of London. This was a documented cemetery not a recent discovery. It reminded me of the known/documented mass grave sites in places in the US like Gettysburg, only the people buried there will not be dug up or studied. I imagine this could have something to do with either the age of the bodies- i.e. older grave sites might seem more like an archeological case study rather than a grave site. Or the other conclusion I came to was space- the US has a lot more space to allow for areas of land to be marked as hallowed, and I am assuming a lot fewer sites where people would be buried.