I'm just curious- if there is no one temporary to pilot the black lion while Shiro's away, (let's be real, they didn't kill him off) how will they form Voltron if necessary? That's the only problem I see with the no black paladin thing
simple: they won’t.
because think about it: they have no idea that lotor even exists, much less that he’s in the picture now. it’s also very likely that they are unaware of the fact that zarkon lived through that final battle. at least for awhile, while the galra get back on their feet and the team figures out what to do next, there won’t be any need to form voltron. not only will being unable to form voltron force them to learn to approach situations with a mindset other than “form voltron and take it out,” it will also allow them to develop within their roles as a member of team voltron, and allow them to come to the understanding that being a paladin means more than just fighting.
there’s also the new developments regarding allura’s magic. considering how we’ve seen her utilize her quintessence to revitalize the balmera, and considering how we’ve seen haggar manipulate quintessence while keeping in mind the new information that she too is altean, we can assume that those newfound abilities will come into play next season. what better way than to manipulate the quintessence of the black lion in order to save shiro & revitalize the lion itself?
but of course, keep in mind that this is all complete speculation and just the things that im personally hoping will happen. the black lion could just as easily be able to be piloted, and we could just as easily see another paladin at the helm for awhile. but we won’t know until we get some information on season 3 itself, so for now, everything’s up in the air.