Technomancers were times better as NPC otaku. Now all the mystery is gone, replaced with hurf-durf matrix mages.
You say that like it's a bad thing. I'd wanted Technomancers since 1st edition. I saw no reason why humanity and the cycle of magic couldn't adapt to technology, and the technomancers were the perfect bridge of the divide. It was already established that the matrix allowed you to project your consciousness into it through the use of technology, it wasn't just 'I can see the net' -- otherwise people couldn't be lost in the machine.
And if the matrix is a focal point for human imagination and awareness, then it would probably have a resonance - an astral presence in some fashion. However, it does not have as much human tradition and the weight of history to give it the strength that we have for magic. It it, however, developing this. We're starting to get preconceptions of what the matrix is, we're adding urban legend and myth to it. There's popular movies, video games, and books defining 'the matrix' as a place and an idea, rather than a thing. Again, this gives strength to the matrix as a concept, and as such, again, it probably would gain astral presence because of this. Given a hundred years or more in-setting, and technomancers would probably be a tradition of magic just like any other, as the understanding of how technomancers work expands.
Hell, consider some of the realms that exist in astral space - the underworld? It exists, but did it exist before anyone could conceptualize the idea of 'the land of the dead'? Most cultures did not have such a concept for quite some time, they thought that dead people were either lost, or trapped in their own bodies, or simply vanished. Were you able to visit the underworld before people knew it existed? Possibly.
In Harlequin's Back, you visit an astral realm that looks like the wild west but with blood magic. That, to me, indicates that there's a lot more in astral space than anyone is aware of - it also let me play with the ideas of what realms people could visit when on an astral quest, or simply exploring the metaplanes. You want to go visit the Japanese heavens? Sure. Do you want to visit the Greek underworld? Of course. But I took it further, and let the PCs visit a Victorian masquerade ball controlled by a shadow spirit, with back-door passages into the underworld as part of an astral quest. Because, why not?
And if those exist... 'an archive of all electronic knowledge' isn't that far of a stretch.