There is no problem with this event. Dylan and Ellie are probably the most important characters besides Sophia in this game. The story between the two of them and Sophia unfolds from the introduction to the present. Both in direct interaction with Sophia and in interaction between the two.
Also, I don't see it as tragic that Dylan has to choose between the second Sophia event and Ellie. The first Sophia event has already taken place and Dylan has already made progress with Sophia in the first update, which could ultimately have an effect on possible Sophia/Dylan/Ellie events. I at least would like it if L&P would include more events like that. That is what AWAM is about from my point of view.
Under no circumstances should this event be cut out. The events with Dylan and Ellie are just too good for that. There are good reasons why the two are so popular, and good reasons why this story-line has so much potential.
Your optimism in all honor, I would be really pleasantly surprised if the new Elli/Christine/Dylan event eventually connects back to the main Sophia path, but I don't believe it will.
While we did play a part of the Sophia/Dylan path for that day when we had Dylan go to the party, since all the other events, no matter which characters, ended up with certain yes/no decisions rather than sympathy points determining further progress on the individual path, I think that ends the Dylan/Sophia path.
When I read a book, I always find it confusing and disturbing at the beginning when the author suddenly changes the narrative perspective. Usually, however, the more the story progresses and the better I get to know the characters, the more I find the change of perspective refreshing. Especially since I know that the author will eventually bring the individual narrative strands together and they are important to the overall picture.
But the fact is here:
1. this new path seems to be a new side path that leads away from the main route and will no longer have any connection to the main narrative thread. And thus it is meaningless to the "big picture".
2. if you don't like the narrative from Dylan's point of view because you don't like the character, you'll never convince anyone it makes sense to keep telling the story this way.
But I have no influence on the way L&P tells its stories and for me personally that's okay. Of course I'm more interested in what happens next with Dylan/Sophia, Elli/Sophia, Patricia/Sophia or, for example, with the museum boys, but I think I'll also be entertained by this upcoming event because I'm neither super critical of a porn story nor specific fetishes have. I want to be entertained and that's always been the case at L&P (for me).