I sure hope not. How is that fair?

I'd guess if it came down to the very wire and the coach had to decide between him and another kid, and the other kid was an unknown quantity and the coach knows that you'll get your kid to practices on time and aren't a PITA, then maybe it would help a little.
Besides that, I don't think it should matter at all. This isn't daycare.

Maybe if you are super involved and supportive as parents..not just as a favor to you but to keep the team support going? But he has to be competitive as a player of course.

Only if they have an unusual rapport from playing together for years. If they've been on different teams this whole time, and don't primarily practice together, I don't see how it would help.

I have 2 sons in MS. both are trying out for soccer. my 8th grader played last year and was already tied by coach that they will be playing this year. my 7th grader is a good player and is trying out. Are his odds increased since his brother is on the team?