I agree with your comment on the FLRW metric. There should be criticism of the assumptions and analysis of the hidden assumptions and silent postulates that comprise the FLRW metric and the Friedmann equations. Omission of caveats and cautionary notes gives tacit approval by Wikipedia and constitutes endorsement. This is contrary to the so-called NPOV policy.
Please see my discussion entries under the FLRW Metric and the Friedmann Equations. They are both entitled Critique of the Universe. This contribution may also be viewed at my Talk Page.