I’d definitely be wary. It could be legitimate, but the fact it’s a new story and they’ve contacted you out of the blue is sending up warning flags for me.
Is the phone number they’re trying to phone you on listed on the verifiable LinkedIn page? That’d be the first thing I’d check, as there’s a possibility they could be claiming a LinkedIn page is theirs, whereas in reality it belongs to someone else.
If it is theirs and it’s possible to verify that they’re from a reputable, legitimate company, ask more questions to get a feel for what they’re looking for from you before committing to anything. If they continue to communicate via Wattpad rather than another form of social media, that in itself is fishy.
Wattpad also has a support page for explaining in greater detail the steps to take if you’re contacted by a publisher: What If I’m Contacted by a Publisher?, which you may find useful to look over.
Hopefully it is for real. But it seems really suspicious, and while it can be exciting at first, it’s always best to do your research before jumping into anything (and it’s good you’re doing so with this thread).
Hopefully this helps a little