Questions have been migrated to localized meta sites have [discussion] tag in English instead of localized base tag.
It is so not so bad. The problem if that a migration will be rejected if the question to migrate doesn't have a tag what exists also on the target site. It is one of the disputable limitations of the question migrations of the SE software.
My suggestion would be to still have the "discussion" tag - but as a synonym to обсуждение.