It is good news. If you watch when they take it up you'll see how much is dust and powder and how much is still solid wood.
I've ripped out most of the floors in both houses now. All the original first floor remains plus the back bedroom, in house #1, as they were replaced with new oak which was OK.
When I ripped out our back bedroom the tongues and grooves vanished into powder but the flooring itself still had quite a lot of strength. The attic, on the other hand had water damage as well as woodworm. When the guy came to fit the Veluxes, he put a foot through the floor.
I still have a pile of wood around 1 cubic meter of old flooring and we've been burning it for 6 years
Good luck but I don't expect you do be having a descending throne issue (makes you sound like royalty), any time soon. Would be pretty nasty if it did as it would shatter and make sushi of your legs... Which is a horrible thought. I was told that by a FIFE janitor who knew about what happens when a toilet cracks when you are on it...