Hmm...first of all, the WT likes to generalize. By using the word Christendom, they generalize al Christians and Christian organisations. There is absolutely no proof they, Christendom as a group, had evil intentions to hide the name. The name was often not used for various resons:
- no alignment of the correct spelling
- NT seems not to have the name at all
- out of respect to God as not knowing the correct spelling
Many translations do acknowledge the tetragrammaton and provide a reason for the chosen translation of it. Most translations made by Christendom have applied a very modest attitude as they decided not to change the NT by adding the name Jehovah in it, like the WT did.
The WT was not the only organisation that used a name for the tetragrammaton. I have a hard copy of the bible from early 1800 (1815) and has the name in it. Various Catholic translation also have a name in it (often Yahweh). Many Spanish translations also have a name.
To use the name or not, is a choice. To add it to NT is wrong as until now, there is not one mss that has it. But to accuse Christendom of evil actions in order to hide the name, is really wrong.