In the sixties, here is what I recall:
The multitude follows Jesus because he feeds them. John 6.
The Jews in the crowd, although I was taught it was the crowd rejected Jesus offer of bread and wine, manna from heaven.
That day the crowd and many disciples rejected the bread and wine of Jesus because they were discussed with his sayings.
After that the twelve were the ones who remained and the new Covenant was offered only to them.
WTS and faithful ones going to the meetings stated this all the time to young children.
It sounded normal and I never questioned this teaching until I was much older.
Only until I started to read in different bibles and wondering why so many teach the church all goes to heaven versus the 144,000 goes to heaven.
Now,I come to a conclusion that partaking has nothing to do with heavenly class or heavenly life. That is made up by Rutherford.
Heavenly life is up to the Father to choose, and maybe Jesus rewards, not any earthly person.
Partaking has everything to do with believing that Jesus is the Messiah, God's son.
Children were told to search our hearts and If we are not choosen to go to heaven that if we partook we would not have life everlasting! It was called, partaking unworthy. Many would frown on some who partook! Later I realized the only criteria bibically would to partake without believing Jesus is the Messiah and son of God. WT loves to confuse people by mixing two or three thoughts together good example partaking,144,000, heavenly hope,and other sheep.
Reading John 6 the JWs neglect the sayings of Jesus! It really is part of everlasting,eternal, life, and everyone who believes he is the true manna should partake. After one dies it is up to God.
Hope that helps some!