upgrading Trisquel versions and Libre Boot encrypted drives question

If one wishes to upgrade from Trisquel 8 to Trisquel 9 and one has bought a Libre Boot laptop with encrypted disk drive does the encryption imply that a different process should be employed when upgrading Trisquel version?

Or can one upgrade simply using a standard command such as described within this recent post, with full disk encryption maintained automagically?
https://trisquel.info/en/forum/how-upgrade-trisquel-8-trisquel-9

I'm imagining optimistically that once you are typing in a Trisquel 8 terminal an instruction to upgrade to Trisquel 9 then you are already working inside the FDE security layer and therefore any changes you make remain inside that encryption security the same as any other change such as installing a new package.

However, I would take comfort from learning the views of other/more experienced Trisquel and/or encryption users so many thanks in advance to any of you who care to offer views or comments on this topic.