I agree with that Watchtower and the two scriptures the OP quoted, also support that.
"Savior of the world." sanctifies Jehovah's name, because the unsaved world tarnishes Jehovah's name.
John 3:16 is not relevant to this issue.
And Jesus would use Jehovah's name. Since he quoted the scriptures that had his name in, it would be a sin for him to change it and not quote it.
Don't throw out the 'baby with the bathwater'. Just because you don't like some things that are taught, does not mean that all things that
are taught are wrong.