You should still change the brake fluid every few years. I don't know what Tesla recommends but most car manufacturers recommend brake fluid flushes every 2-5 years (the Germans generally recommend 2 year intervals, GM generally recommends 5 year intervals, the Japanese brands seem to recommend 3 year intervals).

DOT 3, 4, and 5.1 fluid will absorb water on purpose and disperse it throughout the fluid. Over time if you do not flush out this water-contaminated fluid it'll start to cause corrosion inside the brake system.