Smart Watches first came out on the market at the end of 2013, and became somewhat popular beginning in 2015 when Apple released its first model. They never really took off the way they were expected to, but they did, and still do, have some limited popularity.

3 to 5 years later, some people are just now waking up to their existence.

While smartphones have been the target of rabbinic bans and derision for years already, now finally they are noticing the existence of the smart watch.

I guess that is not good news if you have a smart watch.

The rabbis published a letter in the Haredi papers today saying the people who sell smart watches are causing the public to sin and the entire future of the generation is at tremendous risk.

They mention that nowadays there are many new devices that look like any other device that is not problematic, such as the smart watch, and this is part of the subterfuge employed by the yetzer hara to make it seem like the ban or prohibition doesn't apply to them.

They therefore announce with the notice that this device, the smart watch, is prohibited for use, whether for adults or young people, and this applies even if the watch does not have a sim card or even if there is some sort of filter or a way to block problematic materials on it.
sources: Kikar, Actualic

As I have said before, they will never be able to keep up with the latest devices coming to market all the time. They are two years late to this party but maybe it is because the smart watches never really flooded the market. Maybe a device that gets real popularity very quickly would get a quicker response. Either way, soon your smart watches might cause you a problem getting your kids into schools in the Haredi systems, so be prepared...