> Do they still use 0-terminated strings/char* as the main string type?

Of course, it's still C.

> Is the usage of single linked lists still prevalent as the main container type?

As far as I can remember, the C standard library has never had any functions that used linked lists. Nor are there any container types, linked lists or otherwise, provided by C. So I'd say this is a question about how people teach and use C, not related to the language -- or language spec version -- itself.

I don’t think that will ever change. Will the possibly introduce a more modern string2 type? Maybe but it will probably be unlikely before 2050

Embedded linked lists are pretty cool though.

The C standard library provides no recognizable container types, so there's no "main" anything.