Yahoo! Japan sent out a notification email to the users that their services won’t be accessible in EEA and UK after 11 am, April 6, 2022, Japan time. They also said that Yahoo! Mail, Yahoo! Card, and ebookjapan services will be available after April 6 with limited functionalities.

They advise the users in EEA and UK areas to cancel their subscriptions including Yahoo! Premium, and download/save the contact information before April 6.

See the linked page for the details: https://privacy.yahoo.co.jp/notice/globalaccess.html (Japanese)