I think it was alix who was disturbeed by K and ducky's marriage.
Whomever of the Imperial couple was upset about Kyril and Ducky marrying , Nicholas gave the order of banishment and Kyril father , Grand Duke Vladimir, came to Nicholas to express his anger about it in the bitterest of terms.
The timing of Kyril and Ducky's marriage is of interest as it was in 1905. Well after Ducky's 1901 divorce and also more importantly, after Alexei Nikolaevich's birth. With the birth of an heir , Kyril 's path to the throne was now not so clear.....there was now much more than Michael ahead of him. It was well known Michael had no interest in ruling ...and so after an heir was born, Kyril and the divorced Ducky married. Divorce is not a crime, but I think it would disqualify you from becoming an Empress... and that, imo , would be an issue for Kyril while there was good chance Alix would only produce girls.
Olga Nikolaevna may not have been prepared for the throne ...but it's fascinating how in 1916 Marie Pavlovna seem to think Olga as wife to the shop worn Boris could add legitimacy to the Vladimirovich cause in the coming crisis. ( which everyone seemed to sense ,save for the Imperial couple) Why else would she seek such a marriage at that late hour ? Something was up and Marie tipped her hand badly there.
Also I sometimes think Dmitri Pavlovich was placed at the scene of Rasputin's murder in part, in order to remove him as a possible rival to the Vladimirovich cause... If the Romanov family was serious about over throwing Nicholas...and murdering Rasputin would indicate they thought they were, imo, Dmitri Pavlovich should have been kept completely clear... But did Kyril ever explain what he thought he was doing in turning over his Marines before the Tsar had abdicated ? and did he really think the new order would have any use for a Grand Duke from a Empire that had ceased to exist? Remarkable .