Besides being responsible for the software, Google would design, develop, market, and support the Nexus devices. The various manufacturers would be responsible for some of the development of the phones and tablets that would carry the Nexus name and would handle the production of these devices.
The Nexus 5X also had bootlooping issues leading to a class action lawsuit won by the plaintiffs
These payments could be from unclaimed funds that no one bothered to accept last year. If you did receive a settlement payment last year, you might want to go back to check your bank account or PayPal account to see whether you have received another payment because of the problems suffered by the Nexus 6P.