Don't Install watchOS 6.2 if You Aren't Ready
If you aren't prepared to install watchOS 6.2, you should hold off on updating until you have enough time to make sure you are ready. You may only need 10-15 minutes to prepare, but those are important minutes.
It's hard to say how your Apple Watch will handle the update, especially if you use an older Apple Watch, so you should spend time making sure your Apple Watch is backed up and that you know how it performs on other models like yours.
We have a guide on what you need to do before you install watchOS 6.2, which is a good place to start. You cannot downgrade, so once you install watchOS 6.2, you are stuck there.
While it is rare to lose your data, we've had issues with losing activity tracking for a day or so and having a backup can prevent any loss of streaks, health data and other important things that your Apple Watch tracks.