The tl;dr is that we're finding quite a few red galaxies and red can mean distant (and therefore old) but you need to follow-up and do further direct measurements of each galaxy to be really certain that it's old and not red looking for some other reason.
Some of these unexpectedly red galaxies have been followed up on, and some are indeed old, but it's not enough data points yet to be certain of anything.
The fun part of science is that either way it's pretty exciting!
"These candidates await spectroscopic confirmation: Their redshifts are only estimates for now. But so far, spectroscopic confirmations of other galaxies have confirmed the vast majority of preliminary distances. Even if only half of Yan’s selection turn out to be nearby galaxies masquerading as distant ones, the latter number would still be unexpectedly large."
The tl;dr is that we're finding quite a few red galaxies and red can mean distant (and therefore old) but you need to follow-up and do further direct measurements of each galaxy to be really certain that it's old and not red looking for some other reason.
Some of these unexpectedly red galaxies have been followed up on, and some are indeed old, but it's not enough data points yet to be certain of anything.
The fun part of science is that either way it's pretty exciting!