Well, now that they have sold 5.07 million Nintendo Switches since March 31st (22.86 - 17.79 = 5.07) they could sell 10.93 million more in Q3 and 4 million more in Q4 and make their goal.
reference: https://www.nintendo.co.jp/ir/en/finance/hard_soft/index.html
Q3 and Q4 have much bigger hardware moving software this year, than last year's Q3 and Q4 software.
It is a very risky game release schedule to meet their goals.
If say Animal Crossing and NSMBUD had also released in 2018, then they could have easily surpassed their sales targets by a few million.
They can still sell 37.79 million LTD by March 31st, but they will need both luck and huge marketing budget to make it.