Never say never about who beats who at the trials. Guys who would pull out from another race will start because it is the trials and the reality is a 2:15 guy on a great day can do a whole lot of damage by running smart and having a day while others struggle and others will struggle. We don't know who is hurt, who is going to get sick, who is so worked up they won't race well.
Just ask me or Trent Briney. You show up on the day and you beat guys. NO ONE would pick me over Meb, Abdi, Gilmore, Culpepper, Rohat, Fasil, at the last trials. The would be stupid to but I ran well and they had issues. Four years later I have had my issues and I'm not even in the race.
Now making the team is another thing. Very tough for a guy in that second tier. It happens, but you need to jump to the first tier. Trent came very very close. Conover did it, Pfitz did it. But it is hard. When you are a 2:15 guy you can train for 2:12/2;13 and a good cycle will get you that type of effort. I was 2:15:28 on a downhill perfectly fast course. I ran 2:14:56 on the rolling trials course. would have been 2:12 high on the course I debuted on, probably 2:13 at Chicago or the women's trials course at Boston. So I ran much better. But jumping to 2:09 to 2:11 which is the type of effort it takes to grab 3rd? That is tough. Hall, Meb, Abdi, Gotcher, Hartmann, ritz, Nick have run 2:11 or better. Some of them will run like shit for sure, but half will run at least ok. Thing is if meb and hall run ok and hartmann or gotcher goes for a solid PB then it takes sub 2;10 to make the team. So if you are looking for a surprise in the top 5 or 10 look to the hansons and ex-hanson types. Reneu ran a fast half at grandma's. But if you are looking for a surprise on the team look to the half guys or the 2;11/2;12 guys (hartmann,nick, cabada, lehmkuhle, etc..) Now Conover had run only 2:18 but there were extenuating circumstances.
Sorry about the grammar and spelling, no time to clean it up.