Sadly none, most of the players and tons of new players always wanted 5vs5. This is the popular and a lot more strategic mode. No doubt there were players that wanted to play exactly 3vs3 and still wants to do so, but the future is 5vs5.
SEMC didn’t even want to go that way, but after loosing tons of possible profit and going slowly downhill in player base - they made the only viable choice.
While I like 3vs3, I can’t deny that 5vs5 will turn out to be a lot more deep and potent for things to try out. Also I am sure that drafts will be more interesting as hard counterplay is a lot harder. For example, if you end up on the top line vs countering hero, you can switch lane with other hero and so on. Simple example, but the mechanical skill of given individual while important will not be the only factor ingame after the draft factor. Not to mention how many strategies can be think of.
We will see, but I am sure if you are good enough and when ranked is out (and this will be sooner than later) - you will be high enough to not have 12 years old and if one of such age is into your game, his place and gameplay will be on the right spot.