Not quite accurate. Automatch aims to keep players winrate around a mean based on elo, so it actively tries to bring you to 50% with the intent of assigning you the most accurate possible elo number. If you go on a win streak for instance the system will match you against tougher opponents until you "even out" and regress to what it thinks is your skill level. In theory that means the vast majority of the player base should stick just below a 50% winrate, while the very top players are the only ones able to reach 60%+ winrate levels. Unfortunately in practice coh2's player base is not large enough to support a truly representative system so you see top players with 80+% win rates and mediocre players being matched against the very top by default/process of elimination.
You've confused me a bit. So when you win say, five games in a row, your ELO isn't actually going up each game? Or does your ELO gain per game increase as the streak goes up? Like winning a game at a streak of +12 will have more of an impact than winning at +2?
I thought it was a straight add/subtract with the amount of ELO gained and lost based around the relative ratings of the two players involved, with win streaks being a non-factor.