Copying filtered results - do you still need to Go To Special/Select Visible Cells?

Technically that article has two parts though.
There's actually doing the copypasta and it doesn't matter whether that goes through the ribbon or the tooltip or keyboard shortcuts. Those are all just different ways of giving the software the exact same commands: stuff something into the clipboard, & put a copy of whatevers in the clipboard down.

The first thing it had you do before that though, was change how Excel interacts with the clipboard, using the Copy=>GoTo etc.
So that changes the behavior of the clipboard regardless of which commands you are pulling it from.

Well more broadly I guess the thing is that yeah it's kind of sloppy, but honestly I wouldn't worry about it. Like in these kinds of cases where I'm using filtering to select a data subset? I want to manually check and make sure I've got the correct count of cells in my output range anyway, that kind of thing. I'd be more worried about mis-clicking my selection range and accidentally clipping off data when copying than anything else.

So I don't think you're in any more "danger" than you are from copypasta normally. Just be thoughtful about keeping on top of it and you should be fine.