You will need a new SIM card for the X Pure. This also may use the other network partner GSM so you may have different coverage. You also would be switching to the current My Choice Plan.
The Moto X Pure is an older phones model and is not sold new anymore.
It sometimes pops up as Certified Pre-Owned on the R.W. Store.
If you buy a X Pure elsewhere, please note the BYOP SIM is GSM. But you can request a CDMA SIM (the same network your Moto X1 uses) after you activate the new phone on the BYOP SIM.
As far as “activation” time, the SIM cards them selves have a expiration date, usually a year or 2 away. If you buy a new phone from Republic’s store, you have 14 Days Return Window that starts the day the phone is delivered to you. So if you wait to activate it until after that time, you will not be able to return it or exchange it if it has an issue. Also note, the used Pre-Owned phones do not have a manufacture warranty.