Applied for spouse on 4/27 as a first time AMEX Plat cardholder of any type.
Received 10-12 day notification on browser (and on email within 2 hours).
Reconsideration line (offshore) approved after confirming cardholder and additional cardholder identity (no additional questions).
Spouse is an Ameriprise client, but not relevant to approval.

Also applied same day for AMEX Gold Skymiles to take advantage of combined pulls. Received similar (14 day) hold messages.
Called reconsideration line using application number (not SSN) (didn't want first card approval to muddy this approval decision). Onshore approved the AMEX Gold SM. Asked CSR to overnight the Ameriprise AMEX Plat, who didn't have access to the record (already relinquished to Ameriprise). AMEX systems, upon approval of cards "serviced" by third parties (Ameriprise, in this case) transfers control of the approval record to Ameriprise for processing for approx 72 hours, during which AMEX systems CANNOT modify the record (including the shipping method).

Agent confirmed the fact that Ameriprise "services" this account makes it a distinct product from AMEX Platinum. While a data point only (not conclusive), this agent was extremely competent and detailed in her understanding of Ameriprise card servicing which adds to my confidence in the distinctness of Ameriprise AMEX Plat from internally-serviced AMEX Plat.

Of course won't know conclusively until minimum spend reached/statement closes.