Yes, it's normal to show up in the 2017 tax year. All of that is based on the cash date, not the accrual date.
So long as you accounted for the rechar, and more importantly, attached a statement to your tax return explaining your rechar as the instructions tell you to do, you're fine. You'll be getting forms from Vanguard (1099R and 5498 iirc) which state that you withdrew money from your Roth and contributed to your traditional, but you're not supposed to do anything with them for 2017 taxes because you already accounted for it in 2016.