If an expected starter is injured and not expected to play in week one, but likely to play in week three, he still wouldn't show up on the depth chart in week one. So, as you say, it may or may not tell us something.
A weekly depth chart is supposed to be who is starting that week and who is backing that person up. For example, if a usual starting WR is hurt and not playing, he should not show up in that week's depth chart. Problem is, the Gophers don't traditionally put out a depth chart with any accuracy on a week to week basis. The depth chart they put out each week is hocus pocus.