Can Amazon Kindle have Russian UI? was closed with a message "Questions on Super User are expected to generally relate to computer software or computer hardware in some way".
According to the quoted message the closed question appears to be completel on-topic. So it must stay open on the site.
More detailed argument:
The question is about the software running on this piece of hardware -- Amazon Kindle. Is Kindle off-topic? Probably not, because we even have a tag for it here.
Can the software be configured/updated to have a Russian UI?