Do you feel the audience is too new to understand or appreciate any of these storylines? Is WWE wasting their time doing them? Why or why not?
I don't think that WWE is wasting their time by doing these storylines because they have put together video clips of the older events to help refresh memories of older fans at the same time as introducing those events to the younger fans.
For example, the Bret Hart stuff. Some of the younger fans will have no clue who he is other than maybe that he got into the Hall of Fame. The video clips they put together of Bret's time in the WWE as well as the screwjob did a great job of showing the new fans that Bret was at one time one of the top guys in WWE, was involved with a controversial situation, and is a legend. They knew that after watching the video clips.
Same with Tyson but to a lesser extent. The clips from Wrestlemania 14 were shown and some clips from Raw's leading up to it. The new fans got to see what this was all about. It's not the same as it is to us older fans who remember seeing those events when they originally happened, but it still works and gets the job done.
Revisiting older storylines and feuds to add a conclusion to them is not really wasting any time because it reminds older fans of the original events and the new fans get to find out that at the same time. It's a good way to conclude feuds like Tyson/DX and Hart/HBK/Vince. See what I mean?