It was mentioned in the Guardian football weekly podcast that E Ferguson could still switch to England through his Grandmother I think. From Wikipedia "in September 2020, the 70th edition of the FIFA Congress approved a rule change that now allows players to switch if they have played no more than three competitive matches at senior level prior to them turning 21 including no appearances in FIFA World Cup finals matches or continental finals (e.g. the UEFA European Championship). However, appearing in a tournament qualifier would not". He has 3 competitive caps (qualifiers) so could switch.