Bulk current injection - Resonant frequency of ESD protection diode CAN bus
Yes, you can add more capacitance at the expense of phase shifting data jitter (ISI) 1 to 2 decades down from the breakpoint of line impedance.
But there are also subtle anti-resonant characteristics, beyond the scope here.

Adding caps to power dioes is also done in other applications. 


It is common to see good Japanese Audio Amp designs with bigger caps (e.g. ~ 1 nf) across each power diode in a bridge at line f to suppression RF resonance, when the diodes turn off after very high dI/dt pulse currents.  This is due to parasitic inductance and diode capacitance and high Rs of the diode as it turns off towards 0 bias. 


This results in an RF resonance often in the AM band that can generation 0.6V of RF noise across the diode loop area and generate radiated EMI.  Here reducing rise time with dV/dt=Ic/C does not affect the power diodes from switching current to the bulk caps.



I cannot verify the performance of adding 5pF to this TVS diode. Layout will affect their results and outght to look like this.
  

This is how I graphically compute Q of parallel and series resonant parts.



TVS diodes are good up to 10Mb/s and maybe higher for this part perhaps 100Mb/s BUT NO HIGHER.

For ESD transient protection on VHF,UHF data rate , it is preferred to use Voltage Variable Material (VVM) ESD suppressors have
unique properties of 0.1pF and low ESR.

https://www.littelfuse.com/products/polymer-esd.../xtremeguard-esd-suppressors.aspx     

www.sunlordinc.com/UploadFiles/2011/12/01100729ED707227.pdf     


https://www.onsemi.com/pub/Collateral/TND412-D.PDF