As I think of it, the better solution would be to modify your initial code with something like this:
{{ getUsers.data.filter(user => {
let currentDate = new Date();
let oneDayAgo = currentDate - 24 * 60 * 60 * 1000;
return user.joinDate > oneDayAgo
}).length}}
This code should be placed in the Value
field of your Statistics component.
This way is more efficient because there is no need in triggering getUsers
query just for the sake of calculation.