This pretty much sums up everything right here. Quoted from Organic on foundry
The main thing this provides is exclusivity to “world firsts” and other such things, along with a significant shortage of eyes on potential changes. With pre-launch PTSers getting first crack at Craglorn (Erlexx’s video was cut mid-stream after the second pull in the Trial tonight after hours of lead up to “Craglorn footage”), for folks who are trying to be competitive, it’s a significant advantage. I’m not in one of the more elite guilds for ESO, but I have been competitive in many other MMORPGs. I don’t fault them for using the tools at their disposal, but PTS in MMORPGs post-launch are typically completely open to anyone wanting access so the most eyes can review possible/future content to verify the changes taking place have time for feedback by the larger community.PTS post-launch should be public, hence the name. It’s not a private test server.
That said, at least posting the PTS patch notes goes a little ways toward generating continued community feedback and I do appreciate getting to see them in advance of the patch being pushed to live.