https://www262.americanexpress.com/business-card-application/upgrade/pa/business-platinum-charge-card/upgradeTerms/44926-9-1-WOC0000416#OfferTerms
actually it does (not) have any language...
terms;
50,000 Membership RewardsŪ points
To be eligible to earn 50,000 Membership RewardsŪ points, your request for the Business Platinum Card must be received by 2/19/2017. If your request is not received by that date, you will not be eligible for the 50,000 Membership Rewards points even if your account is upgraded. In addition, you must charge $10,000 of qualifying purchases* on your new Business Platinum Card in the first 5 months from the date your account is upgraded.
Offer is available for first-time upgrades to the new Business Platinum Card only and for one Card account only. Additional Card Members are not eligible. Offer limited to 50,000 additional points per Card account. Offer may not be combined with any other promotional offers. American Express reserves the right to modify or revoke this offer at any time.