Quote from Billiondegree »Seems like a good change. Takes away some of the power of Leyline of Sanctity in being able to protect not only you but your walkers from burn spells.
Some burn spells already specifically mention that they can hit planeswalkers, so this update would simply errata all cards that would previously hit players to also hitting walkers?
Or do all previous cards simply become worse?
It sounds like Wizards will errata a lot of burn spells. So, most burn spells actually get better since most will allow you to hit Planeswalkers directly. As you said, removing the redirection rule will weaken "player hexproof" effects, as the players can go after Planeswalkers directly instead of attacking the player. As mentioned before, if they errata Hurricane and Earthquake-type effects, your Planeswalkers get affected, so those spells become a little worse.
Removing the Planeswalker damage redirect rule and being able to hit Planeswalkers directly also lines up with the rule that creatures can attack Planeswalkers directly in combat.