It's better to beg for forgiveness than ask for permission - the French authorities would probably have objected to full modernization of the lighting, plumbing, etc.
I’m in complete agreement...it was arranged and scripted to be a ‘mistake’, but the place was likely in terrible condition and could not be made livable. I’ve been to the nicer places that have been kept up in Germany, Netherlands and Italy...with tons of money put into a decade-long restoration. If you got lots of government money....you can wait a decade for full restoration. In this case? Erase your issue and start fresh.
I’m thinking of the Tom Hanks movie “The Money Pit”.
You are on to the real story...the costs to do a full renovation would be much, much more than a new manor, so they tear the old place down, say, “oops, my bad” and rebuild with new stuff.
A friend of mine who has a place in France told me today that this is not all that uncommon.