This is one of those cases, like so many, where you can not make one rule and go at the industry with a big paint brush. Some airplanes, as others have noted, have directional control concerns that call for waiting to pull the TRs until the nosewheel is down. Others, such as the 747, have no such problems and can (and on slippery surfaces should) have the TRs pulled as soon as the mains are down.

Do what is right for your airplane in your situation.