This is such an obvious ploy, it probably has the opposite of the desired effect. Uber would've been better served saying Lyft is worth less than their cash on hand because of burnrate / runway and fierce competition. By establishing a $2B floor in what is
clearly a ploy, Uber is
actually communicating that they obviously think Lyft is worth far more than $2B. They just helped establish an anchor of more like $6-8B. If you are Lyft or Qatalyst, this is an exceptionally easy case to make.
The only way this is smart is if they're hoping to help pump up Lyft's price as a comp for themselves, or if they hope to drain a buyer of cash/assets by overpaying for Lyft and thereby lessening their competitive resources under that buyer. Both are stretches and silly bets, though.