Not sure if anyone suggested this, in the tutorials, add more tutorial options, such as a tutorial for people to understand there are items such as dust, smoke, wards, gem and how they work. Also it may be good to add tutorials for certain heros that are easy enough for new players to use, and sort them between support or carry, and teach them the basics of those heros. This way it may allow new players to have to confidence to play pub matches with those certain heros as the heros basics has been explained to them. Although it might mean and increased pick rate in the heros chosen for tutorial mode.