Yes I do think we will still have files (whatever they will be called) at some level for some purposes.
I.e, we will still be able to store and transfer sequences of bytes conforming to some specification (file format), and we will be able to attach names to those blobs in some namespace. The concept is too general to ever lose its usefulness.
There are a few key things I have learned in the third of a century that I've been working with data: Data lives longer than apps and longer than people. We will always need units of data that have their own life cycle and are reasonably self describing and self contained (i.e meaningful without resolving external references).
100 years after their inception isn’t very far from now. There are plenty of people here who will be alive in the 2080s.
Everybody has a different idea of what long term means, but I think of it as millennia from now. The kind of time frame that the Long Now Foundation talks about.
