First thing that came to mind when I read your post was exactly what Terry said. Jesus said do this till I return...well didn't he return in 1914? I mean in their mind not in reality.
A big part of the problem cults have when they make things up claiming some special knowledge is that they don't think things completely through and then find themselves in trouble trying to explain their position which usually leads to more lying and making more things up.
They didn't think it through when the came up with their two class of Christian system. The partakers (heavenly hopers) non partakers (earthly hopers). They didn't look far enough into the future to see a time when their KH would be filled with people passing around the wine and crackers and no one partaking of them in what has turned in to a ridiculous farce doing the exact opposite of what was originally intended.
On their biggest day of the year they gather together to deny communion with Christ. Seems a odd thing for those claiming to be the only true Christians to do.