√ The 1st example has an interface with a Vcm=0 due to the ADC12DJ3200 specs.
X The 2nd example has an interface with Vcm \$\ne\$ 0 for common mode voltage some other ADC. As a consequence it suffers some loss for the same impedance unlike above.
You can follow 1st example since you are using an IC that works at 0Vdc for Vcm