Is it almost certain that all CAT slots will have a DI question??

Hi, we cannot say that with certainty. But, most of the previous year papers had a DI Set.

You can see the past year question papers of IIFT.

What about IIFT though ? Do traditional DI questions appear in IIFT ?

Pure DI is a thing of the past now. DI with LR mixed in it will be what will be asked.