If they wanted to follow the Christian example, they would be called Jesus' Witnesses.
Acts 1:8 But you will receive power when the holy spirit comes upon you, and you will be witnesses of me in Jerusalem, in all Ju·de′a and Sa·mar′i·a, and to the most distant part of the earth.”
It was quite a backflip when they took the name, since Russell said no name but Jesus' should be used .
All true teachers are not only sent by Christ but receive their instructions from him; and any man who attempts to put his own or any other name upon all or any portion of the church is an opponent, an adversary to the true and only Lord and Head of the church." Zion's Watch Tower Oct 1888 p.3
Russell expressed that salvation is through Jesus, which is the core message of the New Testament. It certainly was not Jehovah, which is not a name that appears in the New Testament.
"The correct Scriptural conviction that the only name by which any can be saved is the name of Jesus: - faith in his sacrifice, and obedience and devotion to him."Zion's Watchtower 1901 Aug 15 p.264