I a few universities I know, including my own, cyclic data structures are on the curriculum, but nowhere near being taught as basic or intro stuff. That would lists, queues, trees, and hash-maps.

The regular LinkedList in Java is implemented as a doubly linked list, which is cyclic.

When I took my degree we had one full year of data structures, Data Structures and Algorithms I & II, but they were taught on the third year (our degrees are 5 years).

It occurs to me that these courses have been teaching what might (should?) be considered a naive view of memory; you show me a traditional cyclic data structure and I'll show you a concurrency bug. I suppose that's fine in 1978 when no one imagined they'd be dealing with multi-core microcontrollers, but today, when you find yourself using a "systems" language for non-toy work and you reach for a tool as sharp as a raw pointer, those naive data structures are frequently (usually?) inadequate.

Cyclic data structures are in my experience very useful for concurrency. It's probably the number three good excuse for using a linked list, when you want to hold a lock for O(1) time with no shenanigans. But also, generally, anything that involves communicating information from point A to point B, and waiting on that information, involves some sort of cyclic reference between the sender and listener.

I have to completely disagree ... What are you even talking about? The inability to have circular links is deeply hobbling; they arise naturally in all kinds of circumstances.