Santa’s data collection has always been compliant with GDPR, so he has no need to change his ways. The nature of his data collection is more transparent than most companies, and he is open to updating his records if you contact one of his representatives.
The legitimate business purpose of his data collection is to create a list of those who are naughty and nice this year:
He’s making a list
And checking it twice;
Gonna find out Who’s naughty and nice
Santa Claus is coming to town