This. He’s had 10 years to recognise the pain he caused his eldest daughter due to his nasty attempt to bury your natural attachment to your mother. He must have known how much he hurt you. You were just a kid yet you fought so hard for the keepsake and then you shut down.
I suspect at some level he knows he really screwed up, but rather than deal with it and sincerely apologise, he’s trying to bury your valid feelings of anger, mistrust and feeling unvalued. Again.
He and stepmother also don’t want answer questions about why you have excluded them… makes them look bad. Enjoy it.