The problem with you analogy is that the New Testament churches were observing the Lord’s Supper long after Christ ascended into heaven. There are also accounts that it was observed on a weekly basis. Given that information we can conclude that the Apostles understood that it was not just a Passover meal.
I do not doubt any of your comments here; but there STILL has been no SCRIPTURE presented that shows any change, merely ancedotes about what was or was not observed.