First let me say welcome!
Your understanding is a bit flawed, that is certainly understandable as jw’s have some unusual beliefs to say the least.
jw’s elders dont Partake of the bread or wine either, per say. The jw’s believe only a small number, 144,000 partake. That small number are the only ones who actively share in the communion and share in going to heaven.
The majority of witnesses believe they will live forever on earth. They attend the memorial (a once a year communion held around the time of the jewish passover) as observers but do not actively partake in the communion. They believe they befit from christ sacrfice but do not eat the communion as they not a part of the covenant christ made for hevenly life.
its all a bit convoluted and you have to really really read between the lines in a lot of scruptures and have a whole lot of speculation throw in to get their conclusions but that basics.
i hope that helps, id be happy to answer more if needed