We know that at one point the Vulcans and Romulans sort of "split" and went their different ways. Without a large Vulcan presence, would there be a much heavier influence towards the Romulan way of life to those in that Vulcan/Romulan ancestry? Does that make any sense?
Not to me. They barely know each other at this point to the level that Spock was able to pass off a Vulcan Death Grip as being a totally legitimate thing, and they have had so little contact that the very idea Romulans and Vulcans are related is fairly new to the Vulcans (and if widely known, is so as a direct result of a Romulan committing genocide... not the best PR move).
I think the absence of Vulcans is going to make Spock's relationship with his Vulcan identity ever lonelier. He was pretty lonely as is in a ship full of humans, but there's probably no all-Vulcan crews like the Intrepid out there, Vulcans are an endangered species and I am sure Spock and the Federation are quite conscious of that.
And generally this is a major blow to the Federation it would be difficult to recover from. Not that they're the underdogs, but their galactic situation is likely not as favorable as it was during the original show.