I loved B5. I hate reboots, at least as I understand the word. I have no problem with replacing the actors. That happens frequently in movie franchises. James Bond has been played by a number of actors, and even the gender of a major supporting character was changed in that franchise without calling it a reboot. In my mind a reboot is when the producers and/or director want to take advantage of the name and existing fan base, but decide to do two other distasteful things: First, change key story concepts that have already been established, and second, they usually want to retell yet another origin story. Why is this being called a reboot, and is JMS calling it a reboot himself or are others just misusing the term? I'll gladly go see a new B5 movie (and I really don't go to many movies), but I'll avoid a B5 reboot like I would avoid an Ebola infected missionary. If JMS wants to tell a completely different Sci-fi story then I would welcome that too, but he should not reuse the B5 name, If he wants to pick back up story telling in the B5 universe then he shouldn't try to tear down what has already been done.
On a side note, the list of lost actors from the B5 production should include Tim Choate who played my favorite character, Zathras.