There is this article that I believe you may have seen already: https://kb.tableau.com/articles/issue/view-out-of-date That contains a few different options including ?:refresh=y .
Another option is to the the Tableau Server to "Refresh more often:" this would cause the view to query the data source each time the page is loaded.
Hope this helps!
This is becoming a bigger issue for me because I'm getting more clients that are using Tableau Online.
The problem is that with Online you don't have the dialog box shown above, but also appending the refresh=y to every URL drops users out of the simple way of using native Server navigation when you're opening workbooks.
Hopefully there will be a better option soon, but it seems to be a worsening trend that Online caches the data for 24hrs even though you refresh the data source behind the scenes