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I thought that the forum’s search function could help, but alas, the results are limited to 34 pages x 30 names per page (1.020 names). The Members>Search for Members option allows you to "Search by position", so if you parametrize the search string to "Legendary" it will provide the said 1.020 names, though that is only a partial list, and you’d still need to copy/paste all page results into a unified document to order and/or search through them. Rather than outdated, it's delimited.
Using an end of 2018 database I downloaded at the time, there were 2.218 Legendary members back then. I
normally see around 1 or 2 new Legendary members per week, so I’d expect there to really be something around 2.400-2.600 Legendary members on Bitcointalk.
The list is small, so you could try to PM some of the usual suspects to see if they can provide you the full list.