Excellent discovery! Situational? Yes. But it IS a True Combo. Anyone who's been here since the game launched will tell you that Brawl needs more True Combos.
Jab Locks are a significant discovery for two more reasons:
(1) 14 more characters have Locks (over 1/3 the roster) and can now rack up big damage while carefully transporting the enemy to the edge of the stage.
(2) The original Laser Lock DISTANCES you from your opponent the longer you hold it. Jab Locking KEEPS YOU CLOSE to your opponent. When you finally get to the edge, you can transition neatly into a nasty kill strike.
Yes, Laser Locking can *edit: in theory* carry your opponent to their death, but you need to keep it up long after they've left the edge, and ONLY FALCO CAN DO IT. With the Jab Lock, you can finish your victims off much quicker (and less tediously) with CHARACTERS OTHER THAN FALCO.
In summary - Jab Locking opportunities may be rare, but when they come up, you'll be glad you know what to do.
Thank you very much, sir! Here's looking forward to more breaks like this!
*Sidenote* I'm not a Falco main, so out of curiosity, how hard IS it to set up an opponent for a Lock? I suspect it'd be tough, but if the success rate of even one set-up is reasonable, Locking could become really big with this new info.