The question is moot: it's precisely
because we have evidence of things not currently explained (observation does not fit theory) that we
must postulate that our theory is wrong, or that there is more to discover, or both.
"Dark energy" is a conventional term to describe some energy of unknown source that has the effect of accelerating space expansion with time. We call "dark energy" the thing that explains this observation, whatever that thing might be (we just assume it's some form of energy since it produces motion, acceleration, in a way seemingly opposed to, and stronger than gravity, but for all we knew it could be fluffy creatures from the 7th dimension, "energy" is just an educated guess).
If you remove the observational discrepancy, then you remove the need for "dark energy" to exist in the first place.
The article precisely suggests that:
- there was no such observational discrepancy, rather errors in calculations following observation
- reality is thus shown to conform to our current equations; it's our interpretation of the pretty pictures we took that was wrong all along; this is now corrected.
If true, it's the end of dark energy as a cause because the consequence is gone.
At no point (before or after it's proven or disproven) does "dark energy" imply a postulate on "what it actually is" — and chances are, when we explain previously unknown phenomena, the finders come up with a new theory and ad hoc terminology. Rarely the word sticks when it's just too good an intuition — e.g. the "atom".
Note that "dark matter" is exactly the same, it's a conventional term to denote some matter-like unknown object that has the effect of giving galaxies their characteristic shapes and interactions forming much larger patterns (structure about as big to individual galaxies as galaxies are to individual stars).