NumberSync text messaging for Samsung Watch 2 and Watch 3 is going away by the end of 2024.
AT&T Messages Backup & Sync (AMBS) is going away in December 2024. When it does, Samsung Galaxy Watch 2 and Watch 3 series devices won’t be able to use NumberSync for text messaging. This means when your smartwatch is out of Bluetooth range, you won’t be able to send or receive  text messages.
However, when Bluetooth is enabled and in range of your smartphone, you’ll be able use your smartwatch for text messaging. If you have NumberSync set up and synced with your smartphone’s number, you’ll also be able to make and receive phone calls, even if your watch is out of Bluetooth range.