The previous posts have been already captured. Changing the lastest version of them will not prevent FB from mining all the old stuff.
FB’s business model is to claim that the site is free, and then sell private information to all who will pay. There is no way to fool it, except to post garbage in the first place.
Nothing is free.
This won’t work.
That depends on just how far back they go to mine data. If I was buying data from them, I’d want it to be fairly fresh.
I’ll bet they don’t too far beyond one year back to pull data.
If you’re periodically overwriting old data, eventually the oldest “clean” data will drop off the search sources.