Backups of Apple Watch series 2

I am about to upgrade my iphone and will have to unpair my watch and restore from a backup to the new phone.

I have had my apple watch since 2017 and I can only see two backups in my iphone settings/general/iphone storage/watch. I am worried that if I have to restore from a back up, the two that are available won't have the most up to date data.

I have read that the AW backups are just included in the iphone data backups but if this is so, why am I able to locate the two that I see in my settings - and I understand that there are two because I had to unpair once.

Will I have a choice on which back up to restore from? If so, I wouldn't want either of these unless all the current data is available. Maybe when I unpair it will create a new backup?

Can anyone clarify the new pairing / backup process for me?