Like a lot of us expected, hardware shipments in this quarter were a little on the soft side - it's now 9 months since Switch's last system-seller launched (Super Mario Odyssey). Nintendo's evergreen and mid-tier (DK, Tennis, Kirby) hits have performed solidly, but that's only been enough to keep sales flat over last year. Personally, I find it difficult to see where the upswing is going to come in the July to September period; Nintendo will still be banking on middle-tier titles (Octopath, Xenoblade 2: Torna, Labo #3) and the back catalogue to shift the system. Is that really going to see them land a ~3 million quarter?
I still think Nintendo will get close to 20 million, and might even hit it, but they're going to need an insane second half to the FY. A 10 million plus Q3 is a must - and personally I think that will happen - but Q4 is also going to need to be very strong.
That would put them in the 17.88 to 19.38m range; they'd need to find another ~600k + in shipments to hit the 20 million. Not impossible, if Q2 shows genuine improvement over Q1 - and if Q3 is genuinely insane. This should be a firm lesson to Nintendo, though; they need to work to make sure their system-sellers land more consistently throughout the year.