Those are disabled in tech reborn config in favor of ic2 basic machines. But they add additional recipes which ic2 machines don't have. For example TechReborn extractor can empty unneeded techreborn cells left after processing stuff, or make rubber from slimeballs.
They are disabled by config option Code: # This atempts to fully intergrate TR with ic2 recipes (Beta) B:"Remove Duplicates when IC2 is installed"=true But they have more processing recipes than regular ic2.
If they are disabled in the configuration then it was done by the FTB team for their own reasons, normally balance. We only change things if they are causing issues on the server, otherwise we would be changing the mod author's intent.