Jehovah Witnesses Question about the Memorial?

According to JW's teaching only those who are of the 144,000 going to heaven can participate in communion. The irony of it all is that the number of the 144,000 will all have died out before Jesus returns. Then another failed prophecy of the JW's will have to be revised. Accordingly the 144,000 will remain alive until Jesus returns to the earth. I do not see this happening.