It is possible but it's very rare since sasuke has a pull rate from 800-1200 plus this is a 50% chance you'll get him since the other 50% can pull ay. Before they fixed the pull rate in kage treasure a couple of weeks ago, one or two people were able to get an ultra rare as a free pull but I don't remember how much seal scrolls they used.

You can get Itachi frags in free pulls but I find it easier to find them via 10 pulls. In short, don't expect getting them free but if you manage to then you are lucky.