The 'tibble' package uses the 'lifecycle' package to handle the deprecation cycle.

From ? deprecate_soft :

• deprecate_soft() warns only if the deprecated function is called directly, i.e. a user is calling a function they wrote in the global environment or a developer is calling it in their package. It does not warn when called indirectly, i.e. the deprecation comes from code that you don't control.
• deprecate_warn() warns unconditionally.
• deprecate_stop() fails unconditionally.`

data_frame() contains a calls to deprecate_warn(), we want deprecate_stop() instead, the message should direct to tibble() for the creation of tibbles and vctrs::data_frame() for the creation of data frames. (+ Update in the NEWS).