Quite frankly, I think this new wording is just the “correct” way to word what the spells were trying to do. For all the talk of “natural language,” in 5e, if you read carefully it is clear that the game has very precise and technical logic to the way it words things. The blade cantrips, along with a number of other things in SCAG, didn’t properly follow this internal logic, which is part of why I think WotC dislikes the book so much. Its actual use of natural language leads to a lot of weird rules interactions with the rest of the game (like the old Twin Spell Booming Blade problem.)
This new wording makes the spells work the way the old wording seemed to be trying to work, but in a way that doesn’t cause these rules interaction amiguities. I am very strongly in favor of such a change.
The one thing I would critique about this revised wording is the parenthetical 5-foot radius. It is unnecessary to specify, given that the text of the spells says you make an attack against a target within 5 feet, and neither spell actually affects a 5-foot radius area. This was probably meant to emphasize that you can’t affect a creature 10 feet away with the spells if you use them with a reach weapon, but I think it could cause more confusion than it clears up.
The 5-foot range limitation seems to me to be emulating the 5-foot range of the spells under their original wording, and personally, I don’t think that’s a worthwhile limitation to preserve if the spells are getting errata’d anyway. I will probably be house ruling it to say you attack a creature within the reach of the weapon used to make the attack.
The only side-effect of this errata I don’t care for is the fact that it prevents these spells from being used as reactions with War Caster. That’s pretty annoying, as I don’t think there’s really anything about them that would make them overpowered to use that way. I suspect this is not an intentional nerf, but an unfortunate side-effect of clarifying the wording. I will seriously consider house-rule these spells to be eligible for War Caster despite the range of Self.