Ah, while not taking a position on what one should or shouldn't do, some Airline FFs are pretty laxed and pretty much accept either an image of your elite status card of from that of your online account. Others, CX off the top of my head, requested an itemized line by line account summary of how said status had been achieved, and they do peruse it pretty thoroughly.

With DL, it's variable; for some they'll request the itemized summary similar to CX's practice. For others, the status (challenge) was granted upon a successful submission of elite status card/screen image.

Again, not suggesting what you should or shouldn't do, but I'm from the school where I'd submit it, and roll the dice. I mean, what have you got to lose? Some time writing up and attaching an image on an email?