Is Gramps headed toward GTK4?

While reading some complaints about the ‘flatness’ of the new default GUI theme (libadwaita) in GTK4, ran across a link to the GTK3 ported version.

It seemed reasonable that we might want to experiment with it ahead of time. Can it be added into the master themes?

Cross-reference to MantisBT issue:
0012518 [Gramps] Gramps to GTK4 ; tags - GUI, interface ; 2022-01-01 20:34

(thanks to @GulliblePangolin for the link)