If you dodge during promos it counts as a loss for the promos, but doesn't influence your mmr. There have been some famous-ish people being in bronze 5 while getting matchmade with diamonds as a result. If you want to be matchmade with bronzies though, you need to havve a bronze mmr, which will require legit losses.
I'm fairly certain that they changed things since last season though, so now if your mmr is sufficiently high, you can skip promo series entirely and just be promoted immediately, which would make being a bronze 'diamond' no longer possible. (And getting demoted again would be difficult as you'd lose like 1 lp per game, not to mention be able to avoid demotion for several games even at 0 LP.)