Ranked Flex and "soft reset" in S7?

I know that Riot has said that achieving a good rank in the preseason will be taken into account in Season 7. My question, I guess, is whether the opposite is true: does achieving a crap rank in the preseason mean starting Season 7 SOL?

I guess the question is how deeply does your rank in pre-season impact season 7? Will there be new placements, or did playing right now -- when the MMR is truly useless because it's so early, and major assassin updates and ward changes haven't been learned properly by a lot of players -- absolutely destroy any hope of getting decent ELO in the actual season for me?

Because I was a Silver III/II solo/duo in S6, and I just ended up in Bronze V after flex placements after hilariously mismatched games, quitters, and people making joke picks for solo lanes (I'm a support main, and only a silver-level player, so not much I could do to overcome that kind of thing on my own). I know there will be a separate queue for solo/duo again soon, but I want to know about the impact on flex. If that B5 is carrying over or negating a true reset in S7, I'm probably going to have to write off ever touching Flex again.