Rodrigo here’s my thing with what you said. First off, if they even did a remaster......I hope they correct the ending to 3 because here’s why I say this.
To me synthesis didn’t make the most since game wise to me because if you look at it this way, and this Might be a no duh to most people because of how many times they’ve played through it and considering how old the trilogy is but look at it this way:
Control - This is for the Renegade side: You make the ultimate sacrifice to save the entire galaxy. While your physical body is dead, your mind, morals, and consciousness will live on for all eternity to watch over the people you love and fought to save. The Reapers still exist but as benevolent beings that help rebuild the destruction caused by the war.
Destroy: This was for the Paragon side. And for most of us this was the 'best' ending, yes you lose the geth and EDI when destroy happens. But in the end if you have the perfect ending Shepard lives on, The peace btw Quarians and Geth on Rannoch is invalidated, and The galaxy is finally at peace and free from the reapers, and you did everything you could to save the galaxy. If Shepard dies then he dies as a hero.
Refusal - I didn't like how abrupt it was, I actually chose this one in my first play through and it pissed me off but I somewhat appreciate that we had the option to refuse, if It was up to me; if they did the remaster I say leave this option out. They definitely could have elaborated more on what actually happened this cycle. We lose this round, but the galaxy finally prevails and defeats the Reapers in the next cycle.
Synthesis - The new Synthesis ending is...horrifying. Every organic being in the galaxy is merged with synthetics without any say whatsoever, thus completely disregarding the concept of free will. According to the EDI epilogue, every species lives together in peace, but I won’t buy into it. Why do they live in peace? Just because everyone is part-synthetic now? Synthetics weren't always the problem. Humans waged war with the Turians. The Krogans waged war with...well, everybody. Haha Who's to say it won't happen again?
I’ve said that to say all this. If they make the trilogy remastered; I would correct the ending in Three to where it’s Strictly either the Paragon or Renegade side. Don’t need a neutral (synthesis) side. Make it to where it was like the ending in ME 2. You had the option of either destroying the base (paragon) or control (renegade)