Just like people were lost watching Episode IV because they hadn't seen I through III first? For a 2 hour movie, a skilled writer could have easily ignored a lot of what happened, refer to other things in passing dialogue, and stick to the plot. The Clone Wars, as vast and sprawling as they were in later works, after all came from a single offhand reference in Episode IV. They could have easily started a new trilogy at 45+ ABY with Jaina Solo and Ben Skywalker as main characters, along with R2-D2 and C-3PO still there. All the main movie characters would still be alive for cameos, except Chewbacca. The Empire would still be around, in the form of the Fel Dynasty assuming power. Jaina marrying Jagged Fel and becoming the Galactic Empress would be an interesting end to Episode VII the same way the Yavin Medal Ceremony or the peace ceremony on Naboo was an end to Episode I.