Already been lots of debates/opinions! Many RVers have had a bad experience with the seals leaking, when using EZ-lube, for various reasons. If used properly, proper double lip, undamaged seal, installed correctly, they can and do work for many. A new trailer can have a damaged seal, right from the factory. In which case it will likely leak regardless, just more so from added grease.
Your TH should be no different, just be sure grease used is compatible with grease from manufacturer. If hubs on new TH are not filled with grease, it takes a lot before seeing new grease being pushed out the front.
Jerry