You won't likely get Platinum, if you haven't accumulated all those other 20K points in the current calendar year. Status is not based on your account balance, but on the number of points you've earned each year and must be re-earned annually. An account transfer of points is not like purchasing or earning points as this would be like getting double status credit for the miles, as they'd have applied during the year(s) earned, and this year when transfered. Which is unlikey to be the case.