Enhancing TVS diode circuit
Can the shown figure actually be compared to a TVS diode?


It can be compared to the TVS diode array you referenced.  Both work by having diodes to prevent the signal level from exceeding the power rails by more than a diode drop.


  If so, can the functionality of TVS diodes be improved by adding the current limiting series resistance and a bulk capacitance?


Series resistance, if practical with your circuit requirements, will reduce the stress on any ESD protection device.  The bulk capacitance above, from the ESD protection standpoint, fulfills the same function as the zener in the 8240116, keeping the power rail from moving much.


  Why aren't any of these improvements suggested in the datasheet just like decoupling or bypass capacitors are recommended in every IC datasheet?


Because they don't know your exact design requirements.  Static protection on a cell phone is different from static protection for guys jumping out of helicopters.