Do you still get pinned if you pass an invulnerable save now?
It used to be (i.e. pre-N17) that invulnerable saves were basically for things like forcefields or dodging, so you weren't in fact really hit or pinned. Which means that an invulnerable save would be just the ticket.
Of course, if you are still pinned in N17, then you're right that would be a difference (though the text still seems rather wordy for something as straightforward as a dodge).
Invulnerable saves are used for all sorts of things these days and are much more common in 8th ed 40k than NCE and 2nd Ed 40k. That said N17 doesn’t ever use the terminology “invulnerable save”.
It is always written out the same way as the GSC rules in the rulebooks (check forcefields).
The wording for dodge isn’t exactly short either! And this rule is slightly different as it Only applies on blast and template weapons and doesn’t allow you to reposition the model (I am half expecting the next GW will update the dodge skill in line with this).
Dodge
If this fighter suffers a wound from a ranged or close combat attack, roll a D6. On a 6, the attack is dodged and has no effect; otherwise continue to make a save roll as normal.
If the model dodges a weapon that uses a Blast marker or Flame template, a roll of 6 does not automatically cancel the attack – instead, it allows the fighter to move up to 2’’ before seeing whether they are hit. They cannot move within 1’’ of an enemy fighter.