The whole point of those scenarios is the cross marketing. Free League Alien players buy novels from Titan, Titan books readers may get curious about the TTRPG. Given that brand synergy, I don't see the Titan book scenarios showing up in another format other than the novels for which they were written to boost sales any time soon.
It's possible the scenarios could come to be in another format when the Titan books lose currency (I don't know a lot of specific's about publishing, but I know books have a lifecycle where titles eventually end up on a backlist, and that timeline seems faster these days). You may want to look at the copyright page to see what if any rights are noted to belong to Free League. It's entirely possible Titan "owns" the scanario so Free League can't really do anything with it. I haven't checked out any of the books yet myself, but have been curious. But yeah, these are the first Alien RPG materials without other available formats.
Does Titan put out an eBook version?
Also out of curiosity, it looks like these releases have audiobook format, curious if the scenario gets a narrator too.