I started using EK just after the partnership with SPG closed previously so very glad to see this reopen again! Partnerships like this are surely an absolute win / win for both companies, helping to encourage potentially high value future customers to try your product.
I was beginning to worry that the amount of time it was taking for this to reopen meant Marriott was going to drop EK to partner with just UA/a US carrier instead like Hyatt has with AA. From a non-US resident perspective, I think it reflects positively on Marriott's ambitions that they've chosen to continue with a global airline like Emirates rather than choose a US carrier.