I'm all for tutorial as long as they're not mandatory. What they need is a clear visibility, generally the "We recommend you to play the tutorials" when opening the first time is a good way. People who are willing to try it will do it, the others will just skip it. And they will not have any excuses that "I didn't saw it" as it was right on their face.
But making it mandatory will probably piss off part of the players, they'll start on a negative point, get frustrated because they should play against bots that are unenjoyable, and when they'll finally reach PVP they will port this negative opinion and frustration on it.
New players VS new players might not help to give the answers like today, but the match will be more fair and less infuriating, both for the vets and the new players. The vets will enjoy a more competitive match without the need to explain everything, and the new players will have less pressure on them as they are all learning the game.
Actually I think some improvements in the chat could be a good idea, right now it's just an itty bitty window flooded by everybody. I think a chat with sections (like Warframe does for exemple) could be a good way for both new gamers and vets to discuss and exchange.
SN isn't the simpliest MOBAs, but it isn't a complicated one either. It's just different.
Maybe another good thing is to give some tutorial tips when in game (that you can deactivate ofc), so even if you skipped the tutorial you still have indications on what to do. Like windows saying "you can buy attribute point at your base","Click here to buy attribute points", etc...