I feel ya. It was a emotional low blow for met too and broke my heart. Even though Shepard survived in my ending. And if BW takes the easy way out and just jumps galaxies and go from there, that would be adding insult to injury.
I get that they want the story to be over, but continuation is a big part of the universe in my book. If not as a game, then as part of the story.
So references should be related to savegames and not vague. Which granted, wont be too easy with some of the endings. But since the effects of each ending was pretty much limited to one galaxy... it would work I suppose. But to be fair, I have no hope for anything good to come from the next Mass Effect that will give fans like me, who's heart broke at the end of ME3, that little bit of closure that we need. I till don't understand why an ending like the MAHEM one was no option for them. It would have been ok with fans, I guess, and they had the same starting point like they do have now. I mean, it is basically is the Red Ending without the Plotholes.
The worst thing I can come up with is that the new Main Hero will be part of the final assault on the reapers and when they all jumped to get away from the crucible will be catapulted with a ton more ships of different races into a new galaxy. Or that that happened to his ancestors. Depending on when it will take place.
Edit:
The best possible thing, in my mind, is that in some way they could integrate the new main character being part of the Squad that goes through the remains of the reapers to salvage and/or look for survivors in the aftermath, depending on the chosen ending, would find shepard alive and gets him/her to a medevac, where he/she is reunited with friends or just dont find him/her but others. Before the main plot takes off.
But hey, that's just me dreaming.