Exactly.
And, I think you're right - a lot of pessimism seemed to take hold after people found the end of the ballot period to be disappointing.
And there's another issue, too: The existing Switch titles with online multi-player have all been playable online free-of-charge since the Switch launched, and will be until the paid Nintendo Switch Online service goes live in September.
Even those who are on-board with the service already won't be enthused by simply having to start paying when the time comes, and the existing library's online services going paid without anything else on offer as an incentive won't convert those who aren't on-board.
There needs to be a flagship game to launch the service with. Something like Animal Crossing (which I'm sure we'll see fairly soon) is too relaxed for this, and online-play isn't its focus. And something new that comes out of left-field won't have an in-built audience. Smash, meanwhile, is a major notable omission from the Switch's multi-player library to date, and it's traditional and content-heavy enough to be the ideal title to launch alongside the new online service.
As you say, there's nothing that can do this better!
The thing is, Emily Rogers was one of the sources of most of the rumours that I listed, above. Saying that a Smash game will have a lot of content is a safe-bet in the same vein as "They're going to make another Mario game!", in my books.
More seriously, rumourmongers saying vague, highly-likely things like that also covers for them getting other claims wrong, so that it ultimately looks like they were still right anyway, even though they weren't. It's always a red-flag, for me.
As I'm sure you remember, though, it was astoundingly widely-believed at the time, and was propagated by a number of sources, in spite of its obviously dubious nature.
We're on exactly the same page, here. Every game since Melee has had a poll before it, and Smash 3DS/Wii U did not - I've been almost certain for a long time that the ballot was, in fact, for the next game, with only a little bit of mind paid to Smash 3DS/Wii U.
That, coupled with the amount of time that the "Smash 6" job-listing suggests that the game has been in development for, and the fact that we now have confirmation that the Nintendo Switch Online service will launch in September, makes me think that we could be in for some interesting times relatively soon.