I'm not 100% sure, but the procedure you listed is almost a clean flash. So, yes. Wiping the data also would be better, as this is a major upgrade, from Android 7 to 9.
However, why you want to switch to LOS 16? Its no longer maintained. Last build was on April 7, 2020 and there won't be any update in future.
Also, there are many stable Android 10 ROMs available now; like Pixel Experience, unofficial LOS 17.1, Atom OS, etc. You can try those.
I'm using Atom OS and its working excellent.
Being a web developer, I'm always interested in trying latest software. Hence, suggested you to try Android 10. Anyways, its your choice. LOS 16 is very stable. Its just that it won't get any more updates in future. If you are okay with it, go ahead :good:
* I'm not responsible for bricked devices, dead SD cards, thermonuclear war, or you getting fired because the alarm app failed (like it did for me...).
* Please do some research if you have any concerns about features included in the products you find here before flashing it!
* YOU are choosing to make these modifications, and if you point the finger at me for messing up your device, I will laugh at you.
* Your warranty will be void if you tamper with any part of your device / software.
* Same statement for XDA.
LineageOS is a free, community built, aftermarket firmware distribution of Android 8 (oreo), which is designed to increase performance and reliability over stock Android for your device.
LineageOS is based on the Android Open Source Project with extra contributions from many people within the Android community. It can be used without any need to have any Google application installed. Linked below is a package that has come from another Android project that restore the Google parts. LineageOS does still include various hardware-specific code, which is also slowly being open-sourced anyway.
All the source code for LineageOS is available in the LineageOS Github repo. And if you would like to contribute to LineageOS, please visit out Gerrit Code Review.
As treble has been implemented there are few mandatory changes before you flash this build.
Since a new partition was required for full treble we converted an unused cust partition into vendor which is almost 830mb in size, No we are not re-partitioning your device or anything else which may hardbrick your device