Based on some earlier threads, AA has stated that they will not be honoring TW Lifetime Plat with Lifetime EXP on AA, especially as this level does not exist.
There have been suggestions, though nothing in print except for some reponses to individual inquiries, that AA will in fact honor lifetime TW program miles towards AA lifetime Gold (1MM program miles) or Plat (2MM program miles) levels. By extension, anyone who has TW Lifetime Plat, with 1 million + actual flight miles, would get at least AA Lifetime Gold.