The "LAST EDITED" timestamp on the dashboard gets updated whenever the model is opened even if no changes are made

When you open a diagram by clicking on the name of a model on Dashboard, it opens in edit mode. To make sure there will be no losses of data when leaving the diagram, we invoke save operation. This is the case when someone makes some change, for example adds a table, and immediately closes tab/window/goes to another page. There is no time for autosave, we need to do this when leaving page. Just a kind of "safety guard."

If you don't want to make any changes, you can click "Preview" button on Dashboard, on the right-hand side. This will open a model in read-only mode.

That explains why this was done this way (implementation detail) but it does not make it correct behaviour. If I opened the model with intent to edit but then decided to do nothing it will be marked as modified. This makes the "LAST EDITED" timestamp mostly useless since it does not indicate that the model was edited at all, only when the model was last opened with intent to edit.

As a user on a team, I cannot use this timestamp to check if a model has been updated by someone else. I can never tell if a change was made and I'm just not seeing it or if a change was never made at all!

OK, you're right, this may be misleading. We'll discuss this issue within our team.

We've discussed the issue and we'll fix it soon.