Durian Team have announced Nodes (comp) are going to need/get work done on them for 4K imaging. Tile rendering for reduced memory consumption etc. Maybe some revamped or new nodes added to existing.
But as you say there is no reason not to learn them in fear of changes, they’ll only be improvements not a total change in the way they work on the surface.
Maybe try these software agnostic books:
The Art and Science of Digital Compositing 2nd Edition, by Ron Brinkman and Digital Compositing For Film and Video by Steve Wright they will give you everything you could need to know about the theory of compositing and armed with that you’ll be able to apply it to blenders very basic current comping nodes, plus anything blender may get in the future and any other compositor application you may decide to use instead.