I had contacted Ti about this and this was their reply
Hi,
I cannot speak for the ESD choices made on this specific board design. There are multiple options to address system level ESD and it could be that the designer for this board wanted to show multiple options. These components on this reference design appear to be copied from the BQ76200 EVM schematic - the TVS is not populated on the EVM and is there as another option for ESD protection.
You should design your system level ESD according to your system ESD needs. There are many approaches available, so the reference design might not be using the best optimal approach.
Now, which one should I use? I guess spark gap would be the worst option. Should I use a Flyback Diode or the TVS or is there a better alternative?
Thanks