Instead of having one hitbox with a rehit rate, the move now has two separate hitboxes. The first hit launches opponents at a higher angle (361° → 48°) and has lower knockback scaling (100 → 65), while the second hit consistently comes out on frame 25 (and mostly functions identically to its previous incarnation). These changes make forward tilt connect more reliably.
However, as forward tilt can only hit a maximum of two times instead of three, this reduces forward tilt's maximum damage potential (18% → 12%). As it was practically impossible to land all three hits in a tournament setting however, this does not hurt the move much.
Additionally, this also makes the first hit much less effective on its own if it fails to lead into the second hit (with the move still being unreliable overall, especially at far ranges).