@Dlb731 There's no way to control it as of now, it's all set right at the start of the career's save file. The game probably coded a couple of different scenarios of who and when will retire, then it will randomly pick one scenario for each fresh career.
At the moment the retirements I've encountered were Vettel & Bottas (1st season), Ricciardo (2nd season). Alonso is mostly likely the next candidate with Lewis further down the line (around 5th-7th season if the game follows the same trend as the last 2 years).