Not at all. I do not think your coach will be disappointed. She will be proud that you did your best and you should be proud of yourself as well. And what you have to realize, when it comes to putting a team together, it is not just skill, but also need. So if the team is small and you have 6 great with fantastic tumbling, jumps, etc. you still can only select 4.....the two that were not choosen may have much better skills or a higher level skill set than the backspots of bases selected, but those are the positions that are needed.....so then someone with less skill ends being picked over someone that has excellent skill because the fill a position that is needed.
I hope this helps....Keep working on your skill, and also work on your positions. If you are a side base, work on main basing, if you are a spot, work on basing, if you are a flyer, work on basing.....Good luck and keep working hard.