My tracklight have a Philips HID-PrimaVision PV C 70 /S CDM electronic HID ballast, and being Philips and electronic, I expected it to have high pulse energy and also higher frequency pulses than a regular superimposed ignitor.
Despite this, it restrike my Osram NAV-TS 70W Super 4Y HPS lamp within approx 30 secs instead of instantly, like the same lamp on a magnetic ballast and a VS superimposed ignitor, which have low energy pulses.
Why this is happens?

The capability of an instant restrike is not related to the high vs low energy of the ignitor, but generally to the ignitor peak voltage and then the ballast OCV.
The ignitor energy makes difference only when longer wires between the ignitor and lamp are involved, otherwise with short wiring there is no significant impact at all (assume the same peak voltage). To the contrary, "high energy" ignitors use to have slower edges (their purpose is to work with higher capacitances towards the lamp), which may lead to increase of the voltage the lamp actually need for the ignition (steeper edges tend to break down a gap in gas earlier), but the difference won't be that large, if any.

Plus I see no reason why the ignitor itself should have any different characteristics than a regular superimposed ignitor, after all it uses to be just that.

The electronic ballasts tend to better ignite some lamps mainly because they tend to maintain the higher OCV there without a gap, so it allows the arc to grow fatter just after the first ionization.
On the other hand many electronic ballasts, mainly when designed for lamps that are normally easier to start (like HPS, vs MH), may just chose to not go that high in the OCV, counting on the voltage shape to compensate for that during startup. And this difference may become the difference during hot restart performance.

Plus a significant difference could be in the operating temperature just before the lamp was switched off: If the electronic ballast operates it at a higher real power, the arctube will be hotter, operate at higher pressure, so become harder to reignite.

Definitely these systems are not rated to be hot restart capable, it is just plain luck one of them in your setups is able to restrike the lamp instantly, so neither of them is inadequate or bad for what they are designed for.

@Medved: So how semi-parallel ignitors (Especially of Philips and Tridonic) can instant start HPS lamps, while superimposed ignitors can't?

Neither is rated, nor designed to do so. But also neither is guaranteed to not restrike instantly.
There are some aspects which would make one more likely to instant rrestrike than the other, but other aspects may lead to the opposite, so it is really just a chance of how the parameters, varying within their tolerance,happen to combine so which aspects become the dominant. Many of those parameters are related to the component design, many to just the manufacturing tolerance, many to the exact operating conditions.

It could be the ballast coils that are used with the semiparallel just lead lower lamp operating temperature than the ones used with the superimposed ones. Or it could be just the ssemiparallel ignitors around you happen to generate higher voltages than the superimposed ones, with the next batch behaving completely different. Or the exact mains voltage leads to higher pulse for one type and lower for the other. Or it could be something completely different.