It looks like something is going on with Emirates transfers. Both Chase & American Express are showing similar messages:
Emirates Skywards will be unavailable Transferring Chase Ultimate Rewards® points online or over the phone to Emirates Skywards will be unavailable between 12:00 AM ET 5/29/25 and tentatively 6/30/25. We apologize for the inconvenience.
Citi recently announced that on 7/27/25 the transfer rate will be reduced from 1:1 to 1:0.8. I suspect this is part of a renegotiation by Emirates that wants to be paid more for transfers but that is just a guess.
Hat tip to kawnipi