What is your device? Usually it will be fine, but this also depends on your device.
For example if it was just changed from swconfig to DSA (they switched most targets years ago but some they just changed over), or you are using old iptables config and new targets use nftabels you can have issues and will want to do a new config. If unsure just do a new config.
You can always SSH in and issue firstboot to reset the config so you shouldn't get yourself into much trouble.
Note the devs mostly covered this in the announcement: