If this is a site wide change that you'd like to make, you can make the change just one time in Global parameters
, and that should do the trick.
If this is for a template though that you plan to distribute, you can create a template override
and simply remove the article published date / etc.
I tested this quite a bit this morning, trying to change article parameters using template parameters. In my template, I used php's get_defined_vars() function
to print all the variables in php at that moment. When doing this, it did not include any article data. I tried several different methods, but I couldn't change article parameters when they hadn't been loaded yet.
I'm sure there is a way you can do what you're trying to do it, but I've been running test after test in the last hour, and havn't been able to modify an article paramater within a template. Have you thought about posting your question in the Joomla forums
Let me know if you find a solution, I'm very interested in seeing how it's done.