The concept of a JW memorial is not a regular service eulogizing the death of Jesus Christ, as we do for a family member who has passed away. For JW's and for that matter, other Christians believe that Jesus was resurrected on the third day and has been alive in heaven since.
The primary purpose is explaining the significance of Christ's death. But, it is also called as "Lord's Evening Meal" as mentioned in 1 Cor 11:20. Paul reiterates the concept of 'new covenant' at 1 Cor 11:25, and hence during JW memorials, the concept of the new covenant and the anointed ones are mentioned. Thus, those who are a part of the new covenant are also mentioned and remembered in the memorial.
Since the Governing Body is included in the covenant, they are remembered constantly by the rank and file because the Governing Body keeps reminding them to do so.
Yes, JWs are told to remember the GB. However, in the post we are discussing about the new song used in the memorial, and in my reply to ambersun, I have mentioned that the new song is not just about the GB but about all the 144,00 anointed ones. The theme scripture of the song is 1 Pet 2:9 where the words are mentioned, "Special Possession", "Chosen race". If you read the JW publications, this scripture is applied to all the 144,000, not just the GB.