TNG didn't have Spock as a regular character, and suddenly being a space vigilante with little to no explanation. Imagine if they did, and then went on to revisit Charlie X, with Spock never giving any hint that he'd served on a ship that encountered him before. Would TOS fans not find that a bit distracting?
First off, that's a bad analogy, since Seven never directly interacted with Q in "Q2," only with his son.
Two, I would submit that TNG did something similar with Spock in "Unification," introducing him out of the blue as an ambassador without any "explanation" for his career change from Starfleet. Yes, we can extrapolate that it was an outgrowth of his diplomatic efforts in TUC, but the episode doesn't explicitly tell us that, because it's not relevant to the current story. It also introduces a hitherto-unknown decades-long rift between Spock and Sarek over the Cardassians. It doesn't fill in every bit of the intervening years, because it doesn't need to.
And three, even if TOS fans did find it distracting, they're not the exclusive or even the primary audience. No new series or movie can succeed exclusively by pandering to pre-existing fans, since the percentage of the old audience that's still invested enough (or still alive) to return is too small by itself. Every work of fiction, regardless of its history, should ideally be written in a way that's understandable and satisfying for
new audiences, people who are unfamiliar with anything before it. The story needs to work on its own terms. And that means leaving out continuity references that would be confusing to novices or that would get in the way of the story you're telling, even if that means the veteran audience is left wondering about the missing connection. Because connecting dots is not what the story is for. The goal is to serve the needs of the story you're telling
now. Anything outside of that is unnecessary.
Look at Joss Whedon's
Serenity, the sequel to his
Firefly series. Even though it was a direct continuation, he made some slight continuity tweaks to make it flow better as a story. For instance, the opening flashback showed Simon Tam personally rescuing his sister River when the series said he hired others to do it, and showed him learning something about the experiments on River that he didn't know in the series. This
did confuse fans of the series such as myself, but it was necessary to make the film work as a standalone story and provide exposition for new viewers.
Seven was a soldier when she first came aboard Voyager. That's what she did for eighteen years. That's what she excels at.
No, she wasn't. You're anthropomorphizing inappropriately. Borg drones are not conscious individuals. They're cogs in a machine, neurons in a brain. The Borg Collective is a
single consciousness running on all of its drones' brains in parallel. Annika/Seven as an individual contributed nothing to the actions the Collective made her puppeteered body perform over those eighteen years, so it can't be counted as her personal experience.
True,
Voyager sometimes showed Seven experiencing guilt over "her" actions as a drone, but that was presumably just the way her newly individualized mind was processing and contextualizing the memories she recovered from her time within the hive mind. But that drone wasn't her. It was just a cell in the Collective, no more responsible for its actions than a hair on my finger is responsible for the words I write.
The person we know as Seven of Nine was born when she was severed from the Collective in "Scorpion, Part 2." Her personality was formed aboard
Voyager starting then. It was shaped by the Borg memories and knowledge stored in her brain, but she had not been a distinct person as a Borg drone, merely one small component of the single "person" that is the Collective.
