They could have applied on their own merit. Non story.
Iirc they got their green cards about the time Barron was born. Malania and POTUS often rely on them to stay With Barron as they do not employ a Nanny. BArron learned their language and often acted as a translator when he was very young and they went about NYC ! He is extremely close to his only grandparents.
Because 70 year old retired chauffeurs and factory workers get green cards every day "on their own merit"?