I was under the impression that a third stadium announcement would lead to the game being abandoned - appears that's the case in Germany and is a FIFA recommendation but not yet adopted by the FA.
If the FA were serious about mitigating racism at matches, I think it would send a strong message if Spurs had a stadium ban for one or more home games (with a precedent being set for persistent racial abuse resulting in a stadium ban) but I'm not holding my breath.