I've been wearing an Apple Watch daily since Series 0. I went from that to the Series 4 that I still wear: Black Stainless Steel. It's fast, fluid, and there isn't a single scratch. Having said that, I was preparing for a Series 7 and would gift my 4. If this flat design is accurate, I'll pass. I cannot see how sharp corners on this watch would be at all comfortable. It would dig into my wrist.
Wearing a watch is a very different use case than holding a phone. A watch is strapped to your wrist for 14 or more hours per day. It interacts with your body, your clothing and your environment more than a phone. I assume Apple thought long and hard about these factors in designing the original Apple Watch. To change the design just for stylistic reasons would be a mistake. Function first, then form in my opinion.