Heretic of The Seventh Circle
It's actually directly inconsistent with that errata. The errata exist specifically to make it clear that "attack with a (melee) weapon" does not include unarmed strikes, but "melee weapon attack" does.This is also consistent with the errata that lets unarmed strikes exceptionally be "melee weapon attacks" but says nothing about whether they are "weapon attacks". If it were true that all attacks were either weapon attacks or spell attacks, then arguably this errata would have been unnecessary.
Interpreting "weapon attack" to reference "attack with a weapon" rather than "melee weapon attack or ranged weapon attack" simply does not work with the rest of the rules text.