You take the phone you get to Verizon before you send your trade out. You say, give me a SIM for a phone that doesn’t support it or switch my number to this phone via an eSIM.

Most companies send you the new phone first and you have time to send the trade-in after the fact for a set amount of days. If you do this from Verizon to Verizon as another example the new phone should activate with an eSIM out of the box and move your number. If not, Google is working on a tool to fix that:https://www.droid-life.com/2023/08/22/first-look-at-androids-native-esim-transfer-tool/

This is not any offense to you as your questions are relevant and reasonable, but this post has proved my point that Lemmy users know jack shit about security and why this is a good change. If you want learn there is a good podcast that elaborates on the issue with current physical SIM standards: https://darknetdiaries.com/transcript/118/