The wording does read as if it's a targeted offer rather than a reminder of what the normal requirements are: "To upgrade and enjoy the added benefits of Platinum sooner, an additional 96 Status Credits# and flying the required number of Eligible Sectors^ are needed in the next 2 weeks."
The "sooner" bit suggests it's an offer to get there without reaching the normal 1000 SC threshold.
However, if it is a special offer, 96 SCs is very odd target (why not 100, or 90??), and I agree that only giving you 2 weeks to earn a relatively substantial number of SCs seems a bit pointless - as someone else said, it's unlikely that many people would be willing or able to fly enough to earn that number of SCs at such short notice.
As for the retro claim - I very much doubt that would count for anything. The general rule is that SCs are counted on the activity date, not the date on which they are credited.