the missing animorph, atm im too lazy to go through the books to search fro examples, but in my opinion, the general jist of how them having smartphones could change the situation and affect the story line by: for example, some plot points involves soem of the animorphs stuck in a sticky situation, a fight, and they have to sacrifice one member from the fight to go get the other animorphs for help - like tobias - who alot of the times has to fly around to go get the other animorphs. with phones, they could just text or call eachother. thought-speak range wouldn't be much of an issue anymore, and people could take photos of them morphing and take photos of wild animals doing weird stuff and the yeerks?
thats just what i think. maybe theres more, maybe not. this is rushed, but its cuz im hungry n lazy haha so im gona go eat now.