Just to be clear though, I've never been of the stance that "Bioware needs to learn from their mistakes and fix the trilogy endings."
I am of the stance that they should just 'continue on' in the MW. If this leads right away to them going to Andromeda than that's fine, but it shows they aren't ignoring the trilogy, which is the end result and basis of continuing into a new game. This would also give them a more plausible amount of time to do what they needed for story wise instead of rushing to complete some major projects like the Ark in a few years to escape Reapers. If BW wants a clean slate then why not just label it as an alternate version. So instead of trying to build the Catalyst that they were unsure of, they put all their resources into building an Ark to escape the Reapers by heading to Andromeda. I could get behind that pretty easily. But so far all indication stands that it's the same universe.
One thing that is confusing me is when you say 'main universe', is it not assumed already that everything (MW, Andromeda ext) are all part of the main universe and timeline?
If they do use an alternate universe to tell Andromeda's story, then that fine and by no means would I expect that we would ever have to go back to the main universe at all. But if that's the case, then I would be satisfied with BW just saying, alternate universe.
As for how good the reception is, I take that with a grain of salt because BW stuck to their guns on the ending no matter how bad the reception was for the ending choices, as well as declaring they won't canonize any of the endings, and it's probably the worst reception they have ever had. They didn't change them, so even if the game has a good reception, I see them following through on their vision and not necessarily what the fanbase outcry is for.
So my main focus for another game, is overall continuity in one timeline which you can't have with varying major choices being left.
Wormholes could be the catalyst they use to go alternate dimensions like they did with the star trek reboot.
The Ark was probably constructed after the destruction of Sovereign, the Citadel archives shows that the council did indeed belive the Reapers were real but it was classifeid on the heighest level, Spectres and up could access it, meaning, Spectres going through the archives, or Councilors. A Spectre would need Council clearence to gain access to begin with. (to avoid panic, they also didn't want to edknowledge it in the council Chambers because they had an audience and were being monitored)
Point is, they knew it was a problem that was about to hit them and that thousands of species had been wiped out Before them. Ofcourse they did something.
And as I've said Before, gradeschool physics can solve the disscharge problem, the problem isn't science, it's the commonly used spaceship design that makes sense for short range vessels utilising Reaper Relays.
All you have to do is redesign the core discharge system to instead radiate the charge, rather than conducting or grounding it. And ensure that it can't transfer the energy into the crew section or other sensitive areas.(all of which is easily done if you so desire). You will have to build new ships however, that are designed for long range travel through the vacum of space and disscharge on their own.
I'm guessing this is what the Reapers did, they disscharged in space which is why they didn't need to heatsink or disscharge as often as the ships of the council races.
The Reapers wanted all species to build simpler ships that were dependant on the Relays for travel sicne that made it easier to Clean up the petridish once each experimental run was over. So the Tech left behind would be capsuled ships that disscharge around and on planets to contain travel within tight star clusters. That way they could Cleans one cluster at a time and keep the relays shut down. Like they always did up until this cycle...
After the Ark was completed the Council races started diverting Resources to the Crusible as they became available. Remember, the Asari didn't start sharing Resources until after the fall of Tessia. So it's not an either or deal. The Crusible didn't show up as viable until after the invasion and after Shepard brought the plans from Mars. By which time the Ark would have been mostly completed, or Ark fleet, which ever the case might be.
I prefer the slow way of travel since it's the least space magicy and can be explained using known lore and gradeschool physics to solve the problem of discharging via Radiation.
You will have to excuse the Council for trying soemthing extreme, for the sake of survival, after all, the Reapers had been exterminating thousands of civilisations Before them, what were their chances of survival of their only solution would have been to fight? Close to 0 in any projection I would believe.