I could've sworn VC++6 had Intellisense. I'm not going to dig too far to confirm but Wikipedia seems to agree with me (https://en.wikipedia.org/wiki/Code_completion#Visual_Studio) - it's not a great reference but definitely implies that it was there:
> the Visual Basic versions of IntelliSense were always more robust and complete than the 5.0 and 6.0 (97 and 98 in the Visual Studio naming sequence) versions of Visual C++
I'm also pretty certain it did, and actually that VC++5 (that I'd used as a student) didn't. I'm less confident about go to definition and stuff, but I think that was all part and parcel of the same thing, so VC++6 had it and VC++5 didn't.
(Just like today, it would sometimes fail to work, for no obvious reason, and it was impossible to figure out why, so perhaps for this article it had got itself into one of those situations...)