That's a cynical approach to why various 'Hindu' sects and cults have asserted they're not Hindu. It's often about maintaining the identity of the group or a group integrity and to prevent assimilation. https://twitter.com/urmiundone/status/1254020159376723971

The Brahmo Samaj also asserted their independence from the Hindu identity, although this happened during a more pliant colonial administration (also that members of the Brahmo Samaj included many elite Bengali families). Of course, democratisation would lead to anxieties about

the fracturing of a Hindu identity in the late colonial period and exists today as well. Which translated into many such demands in the postcolonial being quashed, most notably that of the Ramakrishna Mission whose pleas were accepted in the Calcutta HC but rejected by the SC

That did spark the idea this was purely a cynical ploy to gain state support and funding; but you also have to consider the fact a lot of monks within the RK Mission were asserting the differences of their Neo-Vedantism from what they consider mainstream Hinduism prior to it.