According to Kuo, he claims that the Apple Watch Series 4, which is due to be launched later this year, will sport a new-ish design. When we say new-ish, it is because for the most part the watch will look similar to its predecessors, except that it might come with a bigger display, or according to Kuo, about 15% bigger.
As it stands the Apple Watch is offered in 38mm or 42mm screen sizes, but Kuo did not mention if this could result in a larger chassis or thinner bezels. Given how we’ve seen Apple try to push their displays as close to the edge as possible, like with the iPhone X, thinner bezels makes more sense, plus it would also mean that Apple Watch users can continue using the same bands.
Kuo has been right on the money for the majority of his reports, so there is a good chance that this could be true too. However since it isn’t official information, it’s probably best to take it with a grain of salt for now.