I’ve worn an Apple Watch while swimming since the first Apple Watch. At that time Apple stated you shouldn’t, but the reality was that swimming with the Watch was fine. Read this:
The most common question I get about my Apple Watch is this: “Is it waterproof?” Everyone from followers on Twitter to Laguna Beach lifeguards have noticed that I wear my watch while swimming and want to know how this new device holds up when it comes in contact with 71% of the Earth’s surface...
furbo.org
I think Apple wanted to wait to have actual customer data before announcing that the Watch was safe for swimming.
Now, I’m sure there are individuals whose watch was damaged from swimming. That does not mean that event, while admittedly problematic for the owner, was statistically significant or indicative of the overall safety of swimming with an Apple Watch.
If your watch is under warranty you should swim. Try it. Clearly it’s not an issue or Apple would not state this was safe, create workouts for swimming, etc. And if it breaks you can ask Apple to repair the device.
Look, things break. Don’t let fear of broken devices deprive you of their utility. I write that as someone who freaked out over every scratch or ding in any possession.