Thank you for your reply.
Unfortunately that would not work for my use case.
I was looking at a solution that would allow to programmatically remove metaboxes for select CPTs via code.
Currently, as mentioned, is fairly easy to do that when Gutenberg is not active for a CPT, however remove_meta_box does not seem to work for GeneratePress metaboxes on Gutenberg-enabled CPTs.
It might be worth mentioning that same technique works for other metaboxes added by other plugins (for example: Revolution Slider) so I am not sure this is a general Gutenberg issue.