Not quite..
Soy increases AMPK activity. AMPK inhibits mTOR.
PMID: 18420492
But if I may point out, the above is a study using mice. In order for soy (or any other phytoestrogens) to do what it did in the above study you would need to figure out how much soy would be an equivalent amount for humans. So the question then becomes, how much soy does a human really need to consume in order to activate AMPK? Also, if adding something like extra BCAAs or whey to the soy be enough to counter the AMPK and its effect on mTOR?
Again, as I said in my earlier post, as long as soy isnt you main protein source then getting minimal amounts here and there arent going to have a huge negative effect IMO
Also, for what its worth, AMPK will also increase fat oxidation. Within that study above it showed large losses in body fat mass and not fat free mass.