FWIW I had an extremely similar watch pre-2010; I can't compare precisely as it's been years, but IIRC had two Illuminator watches with basically the same face and a fabric/leather strap somewhere between 1998? and 2009. Obviously this person hasn't been there since 1998, just to give a bit of background and I am pretty fuzzy on the timing other than pre-2009. (Not to rule out the same watch still being available in 2009 or later; I just wasn't wearing a watch often anymore so I wasn't looking.)
I agree with those above who advise not putting too much weight on the watch. The light-up function is kind of cool, but I mostly chose it because they were pretty cheap but still reasonably sturdy. I suspect that's likely true of a lot of people who bought them, possibly including the MP.
I also wonder if that's the actual watch in the photo or just a similar one; not to be morbid but those fabric bands tended to absorb sweat and gunk even when not on a decomposing body, and it looks pretty clean... I don't think that means much either way, just thinking out loud.
I hope this kid finds their name and their way home soon.