Well, outside the fact that Mulgrew (and Brenan/Braga shared her point of view about the double standards in gender equity as well in Hollywood as in US society in general -> if they have disagreed with her, don't worry, they would have imposed their choice and Janeway would have been definitively paired with Chakotay!), it was necessary to give an appearance of closure to Chakotay and Seven, who were on their sides, without real emotional ties, while Janeway was married to Starfleet.
I just wonder why Beltran and Ryan waited to announce their concerning/ disagreement about the making of Chakotay/Seven's pairing in Endgame, knowing that nothing led to predict this romance. Strange!
About the choice of Seven instead of Janeway for Chakotay: it's just a theory but maybe Seven was supposed to be an "easy" target for him. I mean, she has very numerous human and intellectual qualities and furthermore, she is aesthetically pleasing to see BUT next to that, Seven is someone who had never experienced truly intimate emotions before, while Janeway is an unattainable woman (proud, clever, independent and lonely (not by choice but she assumes the situation fairly!), who knows how life/world work.
-> in fact, some people would say that Janeway is well out of his league, that he isn't up to Janeway) and frankly, it's true and this in spite of the fact that Chakotay's is a good man.
As for Chakotay/Seven's pairing, I'd say it's a win-win for each of them as long as they are together: Chakotay for the reasons expressed above (a pleasant presence by his side, and where he could be a comprehensive and patient mentor) and Seven, who had to start somewhere. And yes, Chakotay would treat her better than most men ... until she takes more assurance, is more familiar of the world which surrounds her and decides to fend for herself, leaving Chakotay, who is, let's be honest, unable to cope with strong women (ex: Janeway, Seska, etc)!
But fortunately, producers (and Mulgrew) let an opened door for our imaginations. I mean we know what was life aboard with its joy or dispair with but once arrived on Earth, the reality is going to override expectations/dreams. Result: some people will have difficulty in confronting with this new life while some others will marry it easily.
-> I want to believe that Chakotay/Seven in Delta Quadrant is a like summer romances. They don't survive the reality of the daily life (for both, in particular Seven, it will be a leap in the unknown!), because fast, the love magic disappears little by little to give way to the habits and to the disappointments!
