Talks like this reveal the ignorance of Jehovah's Witnesses.
The Watchtower is not the only religion to make changes publically. For example, the largest Church - Catholicism - is well known for its changes, with Synods have been held thoughout history to discuss and modify issues of doctrine. The Second Vatican council, ending in 1965, made changes in an attempt to integrate traditional teachings with modern knowledge. Changes were made regarding liturgy, administrative practices, ecumenism and adding of the doctrine that Mary is the Mother of the church.