We won’t need semantic web if machines are able to understand natural language.
It might get better in later versions but even so, I think passing well-structured data will always result in cleaner output than passing it data with lots of noise.
If we are going to work alongside AGIs, we should consider them equal to humans and by that I mean, passing them good data rather than assuming they'll figure out what we meant. Obviously it won't be _as_ big of an issue or requirement but if you can put into such a format, why wouldn't you?