No? The data for the makeup of energy in the universe is mostly from CMB anisotropy (plus various measures of how fast the universe is accelerating, like how much supernovae have been redshifted). Finding out that galaxies in the early universe used to be smaller and more numerous than previously thought doesn't much affect any of that. (there's quite a lot of different data sources now all pointing towards an omega_lambda of 0.7).

To be clear, per the article, the new discovery isn't about the early universe being a significantly different density (i.e. anything other than 'approximately flat', total omega ≈ 1) than the current one. Like, it's not that there was more mass-energy in it that's somehow vanished, rather that it's just distributed between more & smaller galaxies