I can't help with your questions.. Sorry!
I would however like to say how much I respect your approach.. yes, you are disappointed - who wouldn't be? - but you are not ranting about how you've been "ripped off" or subjected to a "bait & switch".. so^^ to you!!
(I too built one section of a trip around an airlines new config... then due to the positioning flight being late I was rebooked - most efficiently! - onto a flight that would get me to my destination with least delay.. and yes, it was on the OLD config.. natch!

.. A failry common story on FT I suspect!)
Good luck anyway! Hope there is ANOTHER change that is to
your benefit....