I personally found the "Earl of Dumbarton" and Baron "Killkeel" really strange, too. Like "Dumb-a**, first I kill you, then you keel over...-stupid. As if a courtier had made a joke and the queen didn't realise while all around her grinned, waiting for a little baby to be born, to be called Dumb-A**, ääh arton...
If that was planned as it was received, I can imagine that many little stitches led to a big hurt. Oh, I can equally imagine how Meghan came, did not really see but wanted to be victorious and annoyed the elder, senior Royal servants (or however the "grey men" à la Sir Humphrey Appleby were called.) And they were there, probably talking over tea with each other how the new Duchess had such a lot to learn before they could allow her to make her first steps alone. The Palace is a world of its own and when you marry into the Royal family, they will break and mould you so you fit in with theirideas. With the principal in her 90ties, a lot of things surely are done there as they had be done at the time of the queen's grandfather, because that's Court life as the queen grew up in. And Harry as a single man could laugh them off, but Meghan as an "American divorcee" had to deal with them and not many choices.
I still think Harry and Meghan should have kept quiet, a dignified silence and stayed away from journalists. But I strongly believe there is responsibility for that failure of a working Royal-relationship on all sides, not only on H&M.
Dumbarton is a town with ancient royal links. It wasn't supposed to be a "Joke gift". And Kilkeel was meant to recognise a place that has a history of strong unionism. Perhaps there were others that would have suited Harry and Meghan's taste better but they weren't created to make fun of them. And if they refused to use the courtesy title for that reason (and we don't know this is true) then that's their choice to make but also don't cry that Archie doesn't have a title and *gasp* won't necessarily be HRH either.
I pointed out before that whilst many Sussex fans/journalists seem to think that their staff consisted of Sir Humphreys and say so in derogatory terms in reality many members of their staff were young, not British and most were women. This includes one of the people charged with making sure Meghan knew royal history and protocol - Samantha Cohen.
A lot of things are done a certain way but they way to change things isn't to immediately rush in and announce you're the new progressive voice and will be ripping up the rule books. A lot of senior royals do things differently to HM and have their own interests but they don't do it all at once and know when they have to accept certain things as the flip side to all the perks.
The Palace always brief the press, sometimes more wisely than others but some of this information would have been made public anyway like the accounts.