I received the same email on my order as well. So I checked my status on the website and it said I had to update my payment information. Problem is it won't go through. Called best buy CS and they said the bank didn't authorize the payment. Called the bank and there is a pending charge from...
When setting up your pixel for the first time you'll be instructed to connect both phones via USB-c. It should then transfer over along with other things such as photos and various other things.
I just purchased a S6 lite and it's a great middle ground. I was going to purchase a S7 but was able to pick up the lite for $249. If you're coming from a older tablet the lite is a fantastic device. It is also receiving three years of OS updates.
If I had to choose between the two phones you are looking at then definitely going with the Note 10+. That Exynos is a piece of garbage. They can't fix it through software. Slower and battery hungry.