One of the problems of the current system is that {{Noindex}} doesn't work in mainspace - if it did we'd be putting it in the templates for G3, G10 and probably G11 and G12. But if it is now possible to get IT resource to improve NPP then maybe we can start thinking big.
If unpatrolled new articles all had noindex then we'd have some huge painless changes at NPP.
Noindex would mean that Google etc would ignore and not cache these articles or add them to search engine until they were patrolled.
Attack pages and vandalism which currently persist in Google caches would be gone as soon as we'd deleted them.
Spammers who rely on the Google caches and that sometimes their spam persists for weeks would find us a much less tempting target. Some of them might even go elsewhere or try to write in a somewhat less spammy style..
Immediatists who don't want us to accept poorly formatted unsourced new articles could console themselves that unpatrolled new articles were effectively drafts.
Goodfaith Article creators wouldn't get bitten because they wouldn't know their pages spent its first hours or days noindexed, just as today they don't know if their article has been marked as patrolled or not. So no newbies would be bitten by this change, but presumably all the people who wanted to not have a large subset of these articles created would see this as an improvement.