I have a custom list(located in projectX Dept) and I want to have this
list available via web part on another site.

I save the list as a template > Include content > then go to the site
(will say IT Dept)the create a new list from the template I have just
saved. Then add as webpart to my front page.

My question - if I have saved as a template (included content) will
this list update as new content is entered on the main site of the
copy?? (roll up is what I am looking for)