The amended regulations (https://www.legislation.gov.uk/uksi/2022/984/schedule/made) refer to a requirement for connection to a "gigabit-capable public electronic communications network". And a "public electronic communications network" is defined in the Communications Act 2003 as "an electronic communications network provided wholly or mainly for the purpose of making electronic communications services available to members of the public".

So I expect that either type of service meeting the requirement on speed would be acceptable.