Marek has said this isn't the case in one of the livestreams. They are building multi along with the rest of the game but want the core experience working first before releasing that feature.
It'll be at second half of 2026 before that happens i think.
One thing I did notice is that if you own the zelda games on switch 1, and have the online sub +exp, you get the upgrade for free. I'm still not sure that justifies it of course but it's something. Still not sure I can spend that much on a console.