With privacy legislation, GDPR and such it might be necessary to adjust the standard texts that come with phpBB for any separate board. Therefor it is less than ideal, that these long texts are part of the language-pac-ucp.php-file. Between 3.2.9 and 3.3.0 there were several changes to the file, so manual changes to the file had to be included into the update.
For conviniances sake it would be great if the provacy policy and board rules were in a sepatate file (possiby each) or stored in the database. If an update really affects the text, the updater should show the differences and ask the user what to do (merge, override with new, keep current, allow manual edit).
Functionality like this is already around, back from the days, when modifications were a bigger thing.