Why because I loved the movie but I felt it was a reboot of a new hope and if my Theory is ture espsoide eight will be the new empire strike's back. And that's where Boba Fett really had a strong role. I think Kylo Ren will use him to hunt down Finn and Poe, Like Vader did Han Solo in Empire. In the comicbooks and novels, Star Wars it's a cycle of good and bad, dark and light, Just with new players. Kylo Ren is the new Darth Vader. Poe is the new Luke Skywalker, Finn is the new Han Solo, Poe is the new Wedge Antilles. As for Boba Fett I didn't really see anyone that could be him but I do want to watch the movie again. (Future thoery spoiler warning.....) Episode 8 will reveal Rey and kylo Ren are brother and sister. Why I say that because it was something Ren said to Rey about Han Solo being the father you never had! That's right their twin brother and sister like Luke and Leia. That's why Rey was left on a desert planet like Luke to keep her safe from the Sith and the Frist Order. Next my theory is on what part 9 will be.
From part 8 Luke Skywalker will train Rey to be the next generation of jedi because she's force strong. Luke Skywalker now takes on the role of Owbi One and Yoda, mentor, Master, and trainer, the last of the Jedi order. While the Supreme Leader is training Kylo Ren. Ren will probably receive some kind of robotics to his body due to his fight with Rey.
This will take more of his humanity away from him like it did for Darth Vader in espsoide 3. I think Finn may have some kind of robotics added too his body because of his flight saber fight with Kylo. This is where I think Boba Fett will come into play Kylo Ren puts a bounty on Rey and Finn. But he can't find Rey because she is training with Luke Skywalker. Boba fett capture's Finn some how Rey finds outs and she leave's Luke Skywalker tutorlege against his wishes and they will battle again just like Luke Skywalker and Darth Vader did in Empire strike's back. This is how Luke left Yoda to save Leia and Han Solo, because Rey has deep seeded feelings for Finn she will feel he is in danger.
Which will led off to espsoide 9 after saving Finn. Rey will return to Luke to finish off her Jedi training and have a final battle with Kylo Ren who has also finished his sith training. Rey, Luke, General Leia, Finn, Poe, Chewbacca and the resistance which is now the new galactic government because of what happened in part 7, The force awakens. Will crush Kylo Ren, the supreme leader and the Frist Order. Ren and Finn will have the next generation of force strong children because it all part of the Star Wars,Jedi, Sith, dark side and the light side of the force cycle.