Some things to think about:
1) Klecker ran 12:54, 12:55, 12:56 just last year. Just 8 months ago. One other American has done that ... ever.
2) Klecker placed 4th at US nationals just last year in the 5k. Just 8 months ago. The only person missing was Fisher.
3) some amazing 5k marks have been put up this winter. 13:03 for Blanks and 12:57 for Young, etc.. But these marks are one-offs for both, and they reached this level just this year. Klecker has about fifteen sub-7:35/13:10/27:10 marks spread over 3 years.
4) Nur has PRs of 7:40i/13:03i/27:17, the last two set in the last 2 months. Klecker has had some sub-par races this year so far, by his own admission. They were 7:47i/13:06i/27:07. It doesn't look to me like he HAS TO move up to the marathon, unless you think Nur (only one year younger) also needs to.
So, my point IS NOT that he is a lock for either distance, to make the team. My point is that there are about 15 people at each distance that are likely to make it to the final and have a reasonable shot at top-3. Think that's too many?
Fisher, Nur, Kincaid, McGorty, Klecker, Young, Hacker, Beadlescomb, Teare, Blanks, Dylan Jacobs, Bosley, Chelimo ... etc.
The shifting sands of distance running being what they are, mean that if any of these people show up with their best form ever, they likely make the team ... or will be close behind a superior athlete. Nur was a good example of this last year. As Fisher showed last year, if the favorites are just slightly sub-par ... they will miss out.
Only one person on this list has brought their best form to US nationals each year and ALSO made a team in 2021, 2022, and 2023. Joe Klecker.
I don't think he needs to move up to the marathon just yet. If he decides to, it won't be because he has no shot on the track.
Klecker has just as good odds of making the team as Nur, Blanks, Young, Dylan Jacobs, et al until they prove they can reach the starting line healthy, not burnt out, and fresh enough for their best performance. So far most Americans are batting .500 in US Champs the last 4 years.
The most important thing, and one I don't think anyone mentioned, is Klecker didn't run for the 2 weeks before The Ten. Some injury problem, I forget what exactly.