The extended tip couldn't arc to the piston crown if it tried.
It's not electrically viable as the arc takes place from center electrode to ground electrode, (the ground electrode will always be closer than the piston ever could be by a very large margin), and should a plug be fouled enough to prevent that gap jump, the conductivity would revert to going through the fouling into the easiest path it could find: through the body of the plug where its threaded into the head.
However, if running hot cams there is the off chance that the intake valve can slap the ground electrode depending on lift, duration, gap orientation, valve float and revs.