So trying to think on what I would like to see going forward as a way to feel more connected to the game and want to pay more for content and bring players
My suggestion is that for the campaign and story you make this a prologue, an introduction to Imogen, leave the short campaign as a intro to how she got established in the mothership, close out what happened with Karen and the cores and now setup the main campaign.
Maybe the queen was hiding some piece of progenitor technology that opens a new gate to a new unknown galaxy, get the Betusi involved helping us unlock the tech, have Imogen as a now experienced and tough fleet command, dealing with a real threat, bring back the narrator and now write a real meaty sci fi story!
Add a new alien civilisation, add some open space battles (please), bring the universe to life, different characters and stories and then you can keep the current campaign intact as the prologue and now build out a strong 20 mission campaign that can really bring the fanbase back together.
I'm sure you'll be adding content to Wargames but we need the core story to work and rate the game upwards, get people playing and loving the franchise. It needs a big update and something to bring everyone that loves this game together.
I hope you take time and look at this, look at how some studios have listened and worked to bring the game back round. eg Cyberpunk, it needs some big old updates but the story needs a massive one and get this back to being a gritty sci fi adventure - not a kids novel.
Hope this helps or adds an idea, but i'd love to see this and look forward to a proper Homeworld storyline coming in the future