Will anyone break Brody's record?

Eventually.

Chalamet and that Lucas Hedges guy have potential to break the record. Two good-looking guys with great agents.

It's folly to try and judge anyone's ability to break acting records when they are still at the start of their career. Chalamet could go on to be an A-list talent, or he could go the way of so many other younger actors who had promise and failed to live up to it. It's somewhat easier to judge an actress by this metric because of how the industry gears towards younger women and their careers are much more meteoric at first before fizzing out, whereas it generally takes a lot longer for male actors to make their impact and become established enough to be considered one of the greats, but even so, to predict someone will break established records like Streep's or Nicholson's at the start of their breakout is ridiculous.

It's not too dissimilar to how Yorick used to think that no one who currently had a Best Actor Oscar would ever become a three-time winner in that category . . . a year before Daniel Day-Lewis did it. Shit could happen at any time. Chalamet could get nominated next year for his drug-addict movie, or he could be left out in the cold, depending on the luck of the draw (and the quality of his studio's campaign).

Shockingly few actors under 30yo who might have serious talent.  I can't name anyone (!) who can stand with or even come close to talent like Gosling, who was in his 20s when he did Half Nelson, Lars, Blue Valentine etc.  Crazy to think Patric was only 23(!!) when he filmed After Dark My Sweet.  

As for Oscars.... before these noms were announced Jesse Eisenberg was the youngest Best Actor nominee - he's 34!!   Now we have Chalamet and Kaluuya, 22 & 28.  Foreseeably, Chalamet in Beautiful Boy (true story, baity role, Plan B, etc) could be a big contender next year unless he goes supporting.