BuddyPress.org

Hi @mi423.

Yes, this is intentional.

BuddyPress 2.5 uses its own implementation of emails under-the-hood. We no longer use wp_mail. A consequence means that anything hooked to actions or filters specific to wp_mail no longer work. wp_mail_from and wp_mail_from_name is an example of this.
I apologise for the inconvenience.

There are a few ways to achieve this; you can either change the value after the default is *set*, or change it when the value is *read*. For simplicity, I’d suggest the first. This should work though I haven’t tested it:

add_action( 'bp_email', function( $email_type, $email_obj ) {
	$email_obj->set_from( "custom@example.com", "Custom Website Name" );
}, 10, 2 );

EDIT: sample code tested and updated on March 4.