That service ended in the loss of everything the order held.
From the 1870s the Singh Sabha movement, and within it the Tat Khalsa wing, worked to define Sikhism as sharply distinct from Hinduism. Udasi practice (image worship, Brahminical ritual, Vedantic exegesis, ascetic celibacy), was precisely what that programme identified as accretion. The Gurdwara Reform Movement of the 1920s turned the argument into a campaign: after several years of agitation, with considerable violence, the movement expelled the Udasi mahants from the Sikh shrines and transferred them to an elected committee. An act of 1925 defined Sikh identity in terms that effectively excluded syncretic groups.
The order survived in its own akharas, and its status has never been settled. In 2002 the Indian Supreme Court held that Udasi deras are not gurdwaras, a ruling about property rather than about theology, and the shrine committee then declared Udasis to be Sikhs. The legal answer and the communal answer point in opposite directions, and both are still cited.
There is no credible figure for the number of Udasis. They persist chiefly around their akharas in Punjab, Haryana and Uttarakhand, and are frequently counted as Hindu ascetics by observers and as Sikhs by themselves.
The order is worth an entry because it records something the modern tradition has largely written out: that for most of Sikh history the boundary between Sikh and Hindu practice was considerably more permeable than the settled account allows, and that the settling of it was a specific project, at a specific date, with winners and losers.