There's absolutely no harm in removing the meta packages ubuntustudio-*, since that will not remove any of their dependencies.

A meta package in itself is emtpy, such as the package ubuntustudio-video. It doesn't contain anything. It just depends on a list of other packages.

If you upgrade to a newer release, one of the meta packages might have gotten new dependencies - usually new additions of applications that wasn't included before. So, upgrading to a newer release will mean that you don't get new additions to a meta package, if it is not installed. That is the only downside of not having it installed.

If you are only out to do video, then Ubuntu Studio is not essential. You might like to install ubuntustudio-menu though, if you like having things ordered in that way.