Srila Jiva Gosvami states that the news (of Uddhava's relatives passing) was shocking to Vidura, who therefore inquired again due to great curiosity. Thus his inquiry was psychological and not practical

Expressions researched:
"Śrīla Jīva Gosvāmī states that the news was shocking to Vidura, who therefore inquired again due to great curiosity. Thus his inquiry was psychological and not practical"

Srimad-Bhagavatam

SB Canto 3

Vidura asked Uddhava about the welfare of his relatives, although he already knew that they were no longer in the world. This inquiry appears to be very queer, but Śrīla Jīva Gosvāmī states that the news was shocking to Vidura, who therefore inquired again due to great curiosity. Thus his inquiry was psychological and not practical.

SB 3.1.25, Translation and Purport

Then, due to his great love and feeling, Vidura embraced him [Uddhava], who was a constant companion of Lord Kṛṣṇa and formerly a great student of Bṛhaspati's. Vidura then asked him for news of the family of Lord Kṛṣṇa, the Personality of Godhead.

Vidura was older than Uddhava, like a father, and therefore when the two met, Uddhava bowed down before Vidura, and Vidura embraced him because Uddhava was younger, like a son. Vidura's brother Pāṇḍu was Lord Kṛṣṇa's uncle, and Uddhava was a cousin to Lord Kṛṣṇa. According to social custom, therefore, Vidura was to be respected by Uddhava on the level of his father. Uddhava was a great scholar in logic, and he was known to be a son or disciple of Bṛhaspati, the greatly learned priest and spiritual master of the demigods. Vidura asked Uddhava about the welfare of his relatives, although he already knew that they were no longer in the world. This inquiry appears to be very queer, but Śrīla Jīva Gosvāmī states that the news was shocking to Vidura, who therefore inquired again due to great curiosity. Thus his inquiry was psychological and not practical.