Keep in mind that at CDG with AF, the arrival terminal is never guaranteed in advance. You will know it only when you'll arrive at the gate (usually, they announce it on-board while taxiing). It all depends where the A/C you're aboard is going after. When arriving from a non-Schengen country (your case, CAI), you can arrive at 2C, 2E or 2F. So you may be in a position to arrive at 2E, so in the terminal from where your flight to SEA is leaving