Without the original understanding of the Generation, there's really no timeline left. This old system could go on *forever*, just as it has gone on for thousands of years
The Generation change was a turning point for me. I already had trouble with the sheep and goats change and now I saw this change for what it was. It was an attempt to dig themselves out of a hole. The Generation was dying off. Their definition just didn't make sense. Everyone knows what the definition of generation is and here they were making up a new definition that as you said has no meaning at all. The dictionary's definition fits well with what Jesus was saying. Within this generation the end will come and it came within 40 years of him saying it. Even with all the doubts I had it took me another 6 years to be mentally free.
The first "new light" on who the Generation is didn't go over well, so they quickly changed it again with "newer light". This newer light allowed for the big increase in those partaking at the Memorial. So, it served two purposes. It stopped anyone from wondering why the numbers were going up and now they are free of any time restraints. They finally learned from the mistakes of the past not to set dates or limits.