> In the fine print…

Good catch!

> The phone would likely also be locked to T-Mobile US for a period of time after purchase.

Looks like 40 days: https://www.t-mobile.com/responsibility/consumer-info/polici...

> Phones that are designed for (or sold through) T-Mobile US won't necessarily work on T-Mobile NL…

Supported network bands according to https://www.phonescoop.com/phones/phone.php?p=6464:

  LTE   4G
  band 1 / 2100 MHz         IMT (Europe, Asia, Africa, Oceania, Brazil, India, Israel)
  band 2 / 1900 MHz         PCS (Americas)
  band 3 / 1800 MHz         DCS (Europe, Asia, Africa)
  band 4 / 1700 MHz         AWS (Americas)
  band 5 / 850 MHz          Cellular (Americas, Oceania, Brazil, Israel)
  band 7 / 2600 MHz         IMT-E (Canada, South America, Europe, Asia)
  band 12 / 700 MHz         Lower 700 (USA)
  band 13 / 750 MHz         Upper 700 (USA (Verizon))
  band 20 / 800 MHz         EU Digital Dividend (Europe)
  band 25 / 1900 MHz        PCS+G (USA (T-Mobile))
  band 26 / 850 MHz         Extended Cellular (USA (T-Mobile))
  band 28 / 700 MHz         APT (Oceana, Asia, Central America)
  band 38 / 2600 MHz        IMT-E (Europe, Latin America, Asia)
  band 39 / 1900 MHz        DCS–IMT Gap (China)
  band 40 / 2300 MHz        (Asia, Africa, Oceana)
  band 41 / 2500 MHz        BRS / EBS (USA (T-Mobile))
  band 66 / 1700 MHz        AWS-3 (Americas)
  band 71 / 600 MHz         600 (USA (T-Mobile))

  WCDMA   3G
  band 1 (I) / 2100 MHz     IMT (Europe, Asia, Africa, Oceania, Brazil, India, Israel)
  band 2 (II) / 1900 MHz    PCS (Americas)
  band 4 (IV) / 1700 MHz    AWS (Americas)
  band 5 (V) / 850 MHz      Cellular (Americas, Oceania, Brazil, Israel)
  band 8 (VIII) / 900 MHz   (Europe, Asia, Africa)

  CDMA   2G / 3G
  band 27 / BC10 / 800 MHz  ESMR (Americas (T-Mobile))
  band 5 / BC0 / 850 MHz    Cellular (Americas, Oceania, Brazil, Israel)
  band 2 / BC1 / 1900 MHz   PCS (Americas)

  GSM   2G
  band 5 / 850 MHz          Cellular (Americas, Oceania, Brazil, Israel)
  band 8 / 900 MHz          (Europe, Asia, Africa)
  band 3 / 1800 MHz         DCS (Europe, Asia, Africa)
  band 2 / 1900 MHz         PCS (Americas)