Copying Attack w/ Energy Discard Requirement - Compendium Discrepancy?

[Mew*]

Q. If I have a Liepard with 3 Darkness Energies on it and I use "Assist", can I use Charizard's "Scorching Fire" attack despite not having a Fire Energy to discard?
A. Yes, you can. The damage amount is done regardless of whether Liepard has any Fire Energy attached to it or not, but if you do have a Fire Energy attached to Liepard you must discard it. (Nov 29, 2012 TPCi Rules Team)

"If an attack has an energy discard requirement, a Pokémon copying that attack must also be able to do that discard in order to copy the attack. (Mar 15, 2007 PUI Rules Team)
"

These two rulings from the Compendium BW seem to conflict. Charizard's attack requires the discard, so I don't think the first quoted ruling makes sense.

EDIT: After thinking about it, I realize Charizard doesn't have the "... or this attack does nothing" clause. However, the discard is not for an optional effect (like on Landorus EX), so why might it not be considered a "requirement?"

 

[PokePop]

There have been some recent rule changes.
We should review that old ruling.