In 2012, an RFC decided that unpatrolled articles should be NOINDEXED until reviewed and accepted. In 2016, it was implemented differently as discussed here. At that time, it was assumed that new articles would be patrolled within 90 days and it would be sufficient to only honor NOINDEX on mainspace articles for 90 days. The New Page Reviewer user group is at present unable to review articles within 90 days (there is a backlog of 14,000) and requests that the no-indexing of unreviewed articles be extended indefinitely (as discussed here) per the 2012 RFC.
Request: Set wgPageTriageMaxAge to a value higher than 90. Suggested 365 days infinite duration (null) per discussion
Grafana showing pages returning a NOINDEX state: https://grafana.wikimedia.org/d/GDZR_4IVz/pagetriage-debugging?orgId=1&from=now-7d&to=now&refresh=1m