Because it is just a games trailer for an upcoming console? Maybe you look at the games trailer for the Wii U at the E³ 2011 again, what was shown, and what never came. Or maybe you look at the E³ 2011 conference how nice the president of EA was and how excited about the Wii U he was. This
"we have plans for the future" is just marketing speech and says nothing about the real plans. Maybe they have a plan, maybe not, but thinking it will be there for 100% just because they said ONE LINE in a trailer for an upcoming console is just naive.
I did NEVER say there will be NO relevant third party announcements, i say my suggestion is that games like for example Onimusha 5, Metal Gear Solid Delta or Silent Hill f will not come the the Switch 2 after what i saw at the Nintendo Direct. I totally agree with what you wrote
here:
this supposed STRONG third party lineup won't materialize, IMHO, ever, if we are expecting (me, I'm not) something better than what the Switch has seen in the past 6/7 years