I received the email as well. It seems to be targeted according to the term and conditions
Terms & Conditions: **Only Mileage Plan™ members who receive this offer directly from Alaska Airlines via email are eligible to participate. The difference, if any, between the number of miles flown by an eligible member on Alaska Airlines-marketed and operated flights (AS1-999, 2000-2999 or 3300-3499) in 2016 and the number of miles required for the highest 2017 elite status level achieved by the eligible member as of December 31, 2016, will be applied towards 2018 elite status qualification.