US supply constrained for NSW I would guess.
ACNH is running at 50% digital globally confirmed by Nintendo. Nintendo's reported numbers + Famitsu's retail tracking suggests the upper-end for Digital % in Japan is 30%. W26 retail sell-through = 5,001K and Nintendo shipped + digital units through Jun 30 is 7,150K, so using delta of 2,419K = digital = 30%. In reality this number is lower since there is inventory/transit to account for as well as MyNintendo shop hardware bundles.
That puts non-Japan digital share at about 60% to achieve the 50% ratio globally.
US July NPD had Paper Mario in the 300-450K ballpark for retail. TLOUII and ACNH followed right after that, so upper-end for those is Paper Mario minus one unit and lower-end is zero. TLOUII is physical + digital and ACNH is physical only. No idea how to ball-park a lower range since we have little detail about units/hints for software below those two, but I think we know that TLOUII last month was #2 opening all-time for Sony so that puts it at 1.9M in June. So 75-80% drop in month 2 would peg it at 380-475K.
If ACNH is right behind that in the 2-300K range, then with 60% digital it bumps up to 500-750K. So attach rate for ACNH vs NSW hardware is around 1.5-2.5x, which is way higher than what we see in JP for the same time frame. In JP, NSW sold 422K for July 4 weeks and ACNH 279K in the same frame. Add-in our 30% digital and its at 399K - close to 1:1 attach rate. US is somehow 50-150% ahead of that despite ACNH behing a bigger phenomena/driver in JP, which would suggest that HW supply is capping sales and lagging behind demand (which I suspect is currently enough to sustain ~150K weekly sales).