It seems that we are having some changes from those silent in the online Apple store with the 27-inch iMac models. During the afternoon today some models are changing the configuration options regarding SSD disks to permanently remove this option.
At first it seemed that we were facing a possible error or failure of the web but a few hours have passed and some of these iMac models they still don't have the option to configure the SSDs and stays in the basic Fusion Drive with 1TB.
The rest of the options available for configuration remain with 2TB Fusion Drive and 3TB Fusion Drive, So we are not very clear if we are facing a possible formal change or it is simply a misfit of the web.
For now we are waiting to see if this applies to all models or only to models that are right now without this SSD configuration option. The iMacs are all 27 inches and it seems they will stick with this unique Fusion Drive option, at least until a possible equipment update is released if it arrives this year. We may be facing another of those "secret" updates on Apple computers that users and the media discover on the web itself. We will be attentive if they change again or not in the next few hours but let them know those who want to buy a 27-inch iMac that right now there is no configuration with SSD.