If, by history page, you mean the encoding of the lists archives, then yes, you need to run 'bin/arch --wipe' after making the changes to recode the static list archive pages. You also need to recode any lists/LISTNAME/ro/*, templates/DOMAIN/ro/* and templates/site/ro/* templates you may have made. Otherwise, recoding the messages/ro/LC_MESSAGES/mailman.po message catalog and templates/ro/* templates along with changing the character set in th add_language() setting for 'ro' should be sufficient.
If, by history page, you mean the encoding of the lists archives, then yes, you need to run 'bin/arch --wipe' after making the changes to recode the static list archive pages. You also need to recode any lists/LISTNAME/ ro/*, templates/ DOMAIN/ ro/* and templates/site/ro/* templates you may have made. Otherwise, recoding the messages/ ro/LC_MESSAGES/ mailman. po message catalog and templates/ro/* templates along with changing the character set in th add_language() setting for 'ro' should be sufficient.
Did I miss anything?