Providers started announcing that they will shut down 3G networks, starting in 2020 (at least here in the Netherlands, Europe). Among these providers is KPN, the recommended provider by Particle, who will close down their 3G network in 2022. Providers will also stop supporting internet on 2G, basically rendering the Boron 2G/3G useless.
Why does Particle recommends the Boron 2G/3G outside the US/Mexico?
KPN has LTE-M and LoRa
Vodafone has LTE-M and NB-IoT
T-Mobile has NB-IoT and is testing with LTE-M
Tele2 is working with Nokia Wing to provide NB-IoT and LTE-M
The Boron LTE is using the SARA-R410-02B, supports global bands Cat M1/NB1 deployed bands 2, 3, 4, 5, 8, 12, 13, 20, 28.
Boron LTE should work on T-Mobile Netherlands
https://community.particle.io/t/boron-lte-on-t-mobile-nb-iot/39492
Vodafone announcement (Dutch)
https://www.vodafone.nl/van3gnaar4g/
KPN announcement (Dutch)
https://overons.kpn/nl/nieuws/2018/kpn-gaat-in-2022-stoppen-met-3g-netwerk
SARA-R410-02B Specifications
https://www.u-blox.com/sites/default/files/SARA-R4-N4_ProductSummary_%28UBX-16019228%29.pdf