When an article becomes featured (or marked as good quality), it is a good moment to consider it for translation. Users that participated in similar articles may be interested in translating the featured article.
Similar articles can include those in equivalent categories, or linked to/from the featured article.
As an example: Bob, who had edited the article on "Sharks" in Hindi Wikipedia from English, gets a notification when the "White shark" article in English becomes featured: "Hey Bob, the "White shark" article became featured recently in English but it is still missing in Hindi. Do you want to translate it?"