The API endpoint: https://api.mojang.com/profiles/minecraft

Isn't returning a 'legacy' boolean, even though it used to, and it isn't even for accounts that ARE still legacy.

Example: https://namemc.com/profile/AntiNotch.1 This account is unmigrated, but when a request is sent to the endpoint (payload):

["AntiNotch"]

the data returned is 

[{"id":"4f26516ef0044663a38ad2aa4682122c","name":"AntiNotch"}]

This is incorrect in accordance with the wiki: https://wiki.vg/Mojang_API#Playernames_-.3E_UUIDs

The correct response would have been:

[{"id":"4f26516ef0044663a38ad2aa4682122c","name":"AntiNotch","legacy":true}]

Edit: This incorrect behaviour is also visible here: https://api.mojang.com/users/profiles/minecraft/AntiNotch