Looking at the World Standings, which determine starting groups at Worlds, I see 13 Men who could surpass Malinin's 2858 points:
1. Rizzo, with Top 10 at Euros. (Can't earn more points at internationals, which max out at 250)
2. Chen, who could only earn points at international(s), because he's maxxed out on championship points.
3. Messing with 4th+ place at 4C's, or lower at 4C's and points from one international
4. Kvitelashvili, with 5th+ place at Euros, or lower at Euros and points from one international
5. Fa, with Top 12 at Euros. (Can't earn more points at internationals)
6. Vasiljevs, with 4th+ place at Euros or lower at Euros and international points.
7. Tomono, with 4th+ place at 4C's, or lower at 4C's plus international points.
8. Zhou, with 4th+ place at 4C's. (Can't earn more points at internationals.)
9. Pulkinen, with 4th+ place at 4C's (Can only earn 7 incremental points with a win at an international.)
10. Brown -- with 2nd+ place at 4C's, or lower at 4C's if he earned points at one or two open internationals slots.
11. Yamamoto, would need a combination of a lot of points at 4C's -- a win alone wouldn't do it -- plus points from one or two internationals.
12. Sato -- same as Yamamoto
13. Miura -- same as Yamamoto
But only three max of the four Japanese Men who need 4C's points to pass Malinin can compete there -- meaning no Uno, low probability, and no Kagiyama, still a question mark -- so that makes 12, and that's already an unlikely scenario.
Memola, Aymoz, and Britschi couldn't do it mathematically at Euros plus international(s), as all of them would be earning net incremental points only.
If I understand correctly, Chen and Zhou are not competing at Nationals, or even if Zhou is, he'd be in school for 4C's, and Brown is in the same show as Malinin during 4C's. So that makes nine.
Even if three of Tomono, Yamamoto, Sato, and Miura were the 4C's team and earn enough there, and whoever in the latter three earn enough at internationals to surpass Malinin, there are two Japanese Men above Malinin in WS, Uno and Kagiyama, and three who would surpass him. However, only three of them can compete at Worlds; two of their WS become moot, leaving seven, which with Malinin's current rank of 5 would put him in the penultimate group for the Worlds SP, if my logic and calculations are correct.
I don't think it's critical for Malinin to skate in the last group of the SP, although it could be a disadvantage if there's an ice resurfacing between the penultimate and final groups, which depends on the total number of competitors. If he lands his jumps, though, that shouldn't be an issue: it's not like the Men who'd surpass him with Euros/4C's points are that consistent, and even Grassl (2nd in WS) and Cha (3rd in WS) aren't either.