An impossibly huge ring of galaxies might lead us to new physics. Here's how

Feel free to inform my unedufied ignorance.

Early in the Universe things were much more compact/dense.

Mass didn’t just magically appear when atomic nuclei distilled, did it?

If mass existed prior to distilled matter it seems like gravity and possibly black holes might have readily formed when everything was so much more compact, even before identifiable matter.
 
Impressive structure said to be about 1.3E+9 LY diameter at a distance of about 9.2E+9 LY from Earth. My math indicates angular size 360 arcminutes or 6 degrees here and the cosmology calculators for the distance indicate z~1.4 or 1.5, space is expanding faster than c velocity along the comoving radial distance for this structure.

Oops, at 2.82E+9 pc distance the diameter is about 480 arcminute or about 8-degrees across. Still impressive observations here and interpretation using the expanding universe model :)