Legacy just means that license type is no longer offered and so cannot be renewed, although some legacy licenses had a 2-year period where you could renew them although I believe these have all now expired. What this means is that if you renew one of these legacy licenses they will need to be renewed as one of the current licenses, which may have different user tiers.
For example see this entry from the JIRA licensing FAQ about upgrading a legacy license.
Hello! My name is Mark Askew and I am a Premier Support Engineer for products Bitbucket Server/Data Center, Fisheye & Crucible. Today, I want to bring the discussion that Jennifer, Matt, and ...
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