I can certainly see the Yorks doing the work of the Gloucesters and the Kents.
Remember the reason that the Gloucesters and Kents picked up so much work (although their parents had been doing it in the past) because by the time Margaret got married, it was just the Queen, DoE (as their kids were fairly young and Andrew and Edward not even born yet), the Queen Mother, Princess Alice (Countess of Athlone not doing much), you had th DoG in Australia for a bit (not a successful run), the DoK was dead so it was up to Marina, and Alexandra to help pick up the slack. Fast forward 10 to 15 years, Edward is married, in the military, Marina is dead and he and Katherine pick up some work. Prince William die, the DoG has a stroke and can't do anything, and so Richard marries Brigitte becomes DoG (totally unexpected he was training to be an architect), and he and Brigitte starting working for the Firm. They all picked up the slack because there was work tobe done. If that is the case with Beatrice and Eugenie I imagine they would do the same.
And honestly, considering that William (and Harry) don't seem like a they are pressed to be married so we are not sure if they will have wives in 10 years. If they follow some of the other European royals (like Phillipe, Frederick, WA) they didn't get married until their mid to late 30's.
Again, I would like Beatrice to have a more active role. The world is a dangerous place and both William and Harry are in the spotlight with dangerous roles. Anything can happen and we could find ourselves with a Queen Beatrice. She really isn't an awful person she just needs to do a bit of growing up...and so far, other than her dress sense....she has been somewhat okay.