There are two factors working against Chalamet that I think people aren't taking into account.
First is that Call Me by Your Name has been underperforming precursor season. I adore the film and it's one of the most acclaimed films of the year, but it has one Best Picture award, one Best Director award, only seven Best Actor awards (the same as Oldman), no supporting actor awards, only 5 Adapted Screenplay awards (one less than The Disaster Artist), and that's it for awards. On the nominations front, it lags behind Get Out, Lady Bird, Three Billboards, and Dunkirk in Best Picture nominations, Guadagnino has an anemic 4 Best Director nominations, Chalamet has fewer than both Oldman and James Franco, Armie Hammer is a distant third in supporting actor with Stuhlbarg two below him, a tie for most Adapted Screenplay citations, 1 for Original Score, 2 for Film Editing, 4 for Cinematography, and that's it. If you compare to last year's well regarded gay drama Moonlight last year, these results are bad.
I know not everyone watches all the precursors and disregard most of the regional ones, but if the film can't perform better with significantly better average reviews (MetaCritic has it at 93, behind four films, Faces Places, A Fantastic Woman, Dunkirk, and Lady Bird), it's 12th on Rotten Tomatoes (based on adjusted score, which is a bull shit metric, IMO, since it puts Thor, Planet of the Apes, Star Wars, Coco, Baby Driver, Logan, and Wonder Woman above it), but in terms of actual scores, its 97 is which is behind Get Out, The Big Sick, Lady Bird, I Am Not Your Negro, My Life As a Zucchini, God's Own Country, BPM, several documentaries, and a number of other films, and tied with Coco and Mudbound, and a bunch of other films that aren't competing this year.
The second factor that works against Chalamet is his age. If you read my Oscar Statistics article (
http://www.cinemasight.com/oscar-statis ... he-oscars/), you would recognize how tough it is for actors under the age of 30 to get Oscar nominations. Average ages of nominees and winners is over 40. Less than 6% of all Best Actor nominations go to actors under the age of 30 with only one actor in Oscar history, or 1.1% of winners, being in that age range.
Sure, the Academy could turn over a new leaf, but Gary Oldman is an acting legend. He's spoken of as if he's a god who has been maligned and underrewarded by most of the Hollywood establishment. Had his Tinker Tailor Soldier Spy performance not been so subdued, he might have won for that. Yet, this is a major bombastic performance, one that the Academy used to recognize quite frequently and has that Capital A acting that they still recognize. DiCaprio, Redmayne, McConaughey, Firth, Bridges, Penn, Day-Lewis, Whitaker, Foxx, Washington...these are all actors who either gave big, broad performances that were questionably good, or were such major names that that fact may have bolstered their candidacies. Several of them also played historical figures. Affleck, Dujardin, Bridges, Day-Lewis (Blood), Penn (Mystic), Brody, Washington, Crowe, Spacey, and Benigni are the only ones not playing historical figures to win in the last 20 years and only three of those were in the last ten years.