I have seen the thread that you indicated.
What I derive from it as follows:
"This is different from that."(BE)
"This is different than that." (AE)
"This is different to that." (AE)
Do you say I am correct?
You're an intelligent man and I don't have time to read the entire interesting thread right now, so I'll let you come to your own conclusions. I would, however, suggest the "different from" is also AE -- or maybe I've just lived in a BE-speaking region long enough that I don't know anymore.