Released Tuesday, iOS 12.1 brought dual SIM capability for models that support it. But it sounds like you won’t get Verizon eSIM support, at least for now (via PCMag).
Verizon eSIM Support
If you’re a Verizon customer and plan to use two SIM cards in your iPhone, you might have to wait a bit. Although the four carriers promised to support it at launch, Verizon and T-Mobile are lagging.
The problem comes when a physical Verizon SIM is pushed into the “secondary” position while the phone is in the US. Under the current software build, that kicks the Verizon connection down to 2G CDMA, an old network with significantly less coverage than the current LTE network. The old network also has no MMS support, and certainly wouldn’t work for FaceTime. So Verizon customers may find they have perfectly good coverage with their SIM in “primary” position, but no signal and fewer features with the SIM in “secondary.”
This issue doesn’t affect international roaming, so if you’re traveling abroad and want to activate a foreign eSIM and put your Verizon SIM in secondary status, it will work fine. When you get back to the U.S. just remember to put the card back in primary status.