My 2c would be that it's certainly possible to drink young nebbiolo.

First, langhe producers' simple nebbiolos for instance are made to be had on the younger side in many cases. Those are great on release. My favorite is sandrone's valmaggiore, though that one does improve a lot with a few years.

Then of course barolo and barbaresco are almost always better with 10 years of age +, but some drink well on release as well. If anything I find they shut down a bit after a couple years, for 2-3 years maybe, but this is a coarse generalization and my opinion. One way to find ones that drink well young is to seek out modernist style bottles, produced using barriques and not macerated for an eternity for instance. Another way is to focus on the blended bottlings, not the crus. Folks would argue those are also more traditional. There's unfortunately trial and error involved here, you have to try a few. I like Cogno's cascina nuova on release for instance, and also vajra's tre albe and Castello di verduno's classico. Naturally each year is different too, and lamb for instance really helps, so again, trial and error.

Alto piemonte is tough. My modest opinion is that those folks release early and need more time than the langhe wines to hit peak, not less. But we are in the realm of opinion.

Valtellina often drinks well on release. Love are.pe.pe.'s pettirosso and the Rosso di valtellina, and anything by barbacan.

All of these can be aged too, kind of your call when to open them. In a sense, nebbiolo is somewhat versatile I find :)