Each device can deviate a bit between devices and runners. So, your power can be a few % different when you get a new Stryd as compared to your older device.
If you buy the new wind Stryd, your power will likely be a bit higher as we now account for the power needed to overcome wind resistance.
If you use auto-CP, your critical power may need some time to fully adjust. Eventually, your CP will be adjusted fully to your new device (maximum of three months).
If you need additional assistance, contact firstname.lastname@example.org.