All prospective international students coming to study in the UK on or after 1 January 2021, will need to apply for a Student visa and receive a decision, before they arrive. This includes those who begin their course remotely in autumn 2020.
EU, EEA and Swiss students resident in the UK by 31 December 2020 should not apply for a Student visa through the new points-based immigration system. They, and their family members, are eligible to apply to the EU Settlement Scheme (EUSS). Those resident in the UK by 31 December 2020 have until 30 June 2021 to make an application.
Further information for EU Students: https://www.gov.uk/government/publications/uk-points-based-immigration-system-eu-student-information
Source: Government of the United Kingdom