So you aren't looking into losing weight on ww? just maintain? If so, you should be fine.. The only way you would gain weight is if you had a really slow metabolism and your body doesn't burn apx 2000 calories a day - but that's rare and there are ways to increase your metabolism anyway (water, exercise etc..)
I'm after moving from TFR on lipotrim to ww to lose my last few pounds - lost a half pound last week on my refeed and have my 2nd weigh-in tonight after doing ww properly all week so we'll see!!!