they've stated there will be SKU's with LTE "later this year".
https://www.microsoft.com/en-us/surface/business/surface-go - scroll down to
2 LTE capability coming soon. LTE support available with i5 models only. Service
availability and performance subject to service provider’s network. Contact your
service provider for details, compatibility, pricing, SIM card, and activation.
See all specs and frequencies at surface.com. Availability of data plans for
eSIM varies by market and by carrier.
>Will the Surface Go have LTE connectivity?