I don’t think conservatories care at all. Frankly, the top ones don’t even care if you play in orchestra at all, at least for string players. If you are going for Ivies or other more academic programs, it might be considered, though.
Having said that, many programs/youth orchestras do require you to play in school orchestra if you are able to (my son’s scholarship program requires it, for example), and a lot of people consider it a bit of a service opportunity. But if you cannot fit it in, I wouldn’t be too concerned.