For the purpose of determining whether at any time a tenant of a housing association was a public sector tenant and his tenancy a public sector tenancy, the association shall be deemed to have been registered at that time, under F1Part 2 of the Housing and Regeneration Act 2008,F2Part I of the Housing Act 1996 or Part I of the Housing Associations Act 1985 or under the corresponding Northern Ireland legislation, if it was so registered at any later time.