I highly doubt there would ever been a reboot of the series for the fans who since grown up, the relaunch failed and somehow I don't think KA is interested in the series anymore. That said if I had a magic wand and could make it happen here is what I think a reboot would involve, some good things some bad.
The good:
1. Older characters from the start. The characters were around 13 in the first book I think a reboot would have them be 17-19 as people of that age have more dramatic options open for them.
2. A focus on sexuality: The two main romantic sub-plots of Cassie/Jake and Rachel/Tobias were left for the most part at Disney Channel level action maybe once or twice creeping up to ABC Family levels. A mature reboot would necessarily go all out on how physical the characters got but I think "fade to black" moments would be almost a certainty. You don't stick healthy teenagers in high stress situations, have them have to rely on each other to live or die and have them not get ideas.
If it was done tastefully it could really add to the characters. For instance I'd see Rachel as the one to instigate things with Tobias, hell maybe even have a reverse of the classic "he wants to go all the way, she wants to wait" story line (a story line that I'd love to see done even if not in the Animorphs) while Cassie and Jake would more likely "just happen." One of them would be comforting the other after a particularly grisly battle and one thing would lead to another.
3. Drug use and possible addiction: since the Animorphs were younger in the original books I think their access to drugs and alcohol would have been limited. Older characters would likely already have had an illicit drink or two and its not hard to find harder stuff if your willing to look at most high schools. The stress of their new lives could very well lead a few of them to seek solace in self medication. Its also possible one or more of their parental units would have them put on medication once the night terrors began.
4. More focus on technology: In the late 90s the internet was still more or less a cool side show to start a plot line, it hadn't become as crucial to our lives. Now every Animorph would have been on facebook and twitter and every morph and demorph would be risky since you never know when some airhead with a camera phone (which is every airhead in the country now) might catch them. They would enjoy a brief spat of youtube fame before they were infested (and worse, demonitzied).
5. This is more a personal preference but Rachel could not die and we could avoid the ruddy "ram the bladeship" ending.
6. There's a chance there could be a few funny moments when the Animorphs infiltrate a "furry" convention.
The Bad:
1. Forced retcons for "diversity:" right now there is a bit of a cult movement in YA literature around having diverse casts, Animorphs was racially diverse from the get go and took a fairly colorblind approach to it. That approach is now considered tantamount to bigotry in some circles, many people would demand that the characters ethnicity become a bigger part of their character. Marco would become an undocumented immigrant, Cassie would become a constant victim of profiling, Jake and Rachel would deal with antisemitism. One or more of the characters would be rewritten as bi or gay and any objection to these changes would be shouted down as bigotry.
It's important to note a key word in the above point "forced:" focusing more on the identity of the characters and how their religion and race mold them isn't always a bad thing but its nearly impossible to do without seeming like your forcing it and derailing the main plot for a PSA on whatever pet political cause in en-vogue at the moment.
2. An overly political focus: KA and her ghost writers got political in a few books and those were generally low points in the cannon. Today's world is so hyper politicized that some people demand celebrities and artists who just want to create art take a stand on various issues, even though many already do so without being asked. People looking for an edgier retelling of their favorite book might find themselves subjected to a 300 page screed on why the filibuster is bad.
3. Getting too edgy:
While taking a look at some more mature topics would be good there is always the risk of taking it too far and winding up a Riverdale like bastardization of the source material (pleas note, I'm saying Riverdale is bad, I've never seen it, but it's a far cry from the original comics). Instead of having Rachel and Tobias having a physical relationship we'd have Rachel getting pregnant and getting an abortion, instead of having a few of the Animorphs taking solace in booze or dope we'd have Marco almost overdose on black tar heroin in a bad part of town.
Those are my thoughts at least, feel free to disagree with me as I am far from infallible. What do you guys think would be a part of a more mature reboot? How do you think the characters will change? How will the they stay the same? How much of a change would you expect in the series.
