Why i think Shepard's story isn't finished.

Is it that easy? What would you say that would convince me that you were the former human called Shepard? Why would I believe what the thing says? That so-called connection with the green, is the catalyst in control? If it is, it's likely has everyone believing what it wants them to believe.

If Bioware wanted ME3 to be the end of Shepard, why have the guy at the end say the details have changed, it happened along time ago, and one more story?

As far as the green and blue are concerned. I would not be surprised if the majority of people who played ME3, wouldn't have a problem if Bioware chose destroy to have a game that continues after the events of ME3.

Anecdotally, didn't we figure that the overwhelming majority of players had gone with DESTROY (I have 80% in my head)? That may have come from the huge survey that was run in the aftermath of ME3. 

There was definitely the sense that BW's preferred option was Synthesis - didn't Mac rave about one of the Deus Ex games? Having said that though, I don't think they saw the utter revulsion that most people had for the green ending coming. Picking Synthesis as a canon ending wouldn't be brave, it would be suicidal. 

Something else to bear in mind - didn't BW's own infomatics shows that the majority of players didn't even finish ME3? Casual players, who will be the primary target for a future game, won't care less what ending they go with because they never had any skin in the game to begin with.

Oh come on nothing.  No one knows how long it took to have everything rebuilt. I like to see a link to a quote or video of the person who said 500 years.

No. You're being petty because I asked to see a link for what was said. Regardless of how long it takes, a game can take place during that time.

I'm sure if that were to happen, I would imagine fans would like to see the other characters, that were with Shepard, return as well.

I don't see that happening. I predict there will be another ME game being released sometime in the future.

I'd actually find that one game of that oddly hopeful, if played the right way.

For example: shortly after contact with Shepard is lost, the Reapers converge on the Crucible, wear away at the Shield fleet, and finally destroy it. Hackett's final order to the Normandy, where the Virmire Survivor is now in command, is "Initiate Zeta Contingency." The color drains from everyone's faces as the VS orders the crew to cut all communications, initiate stealth mode, and withdraw to the Charon relay for one last mission: to gather the resources necessary to replicate and hide Liara's archive in enough places that the Reapers can't find all of them before the advanced races of the next cycle discover it. They'd be fighting not for themselves, their loved ones, or even their species, but to make sure that people that they'll never meet will have a chance thousands of years in the future. Maybe the game would end with Harbinger destroying the Normandy just after the crew finish wiping all traces of the data archive and of where they've hidden the copies, but they die content, knowing that they accomplished their mission and that the next cycle might finally be the last.

Bioware could continue Shepard's story if he/she refuses to choose an ending.

After standing for x amount of time, a shuttle comes to Shepard's location. The reason is that Hackett was running out of time and wondered what happened with Shepard. Back on the Normandy, Shepard doesn't reveal that she/he chose not to pick an ending, but instead said she/he couldn't find a way to make the crucible work. At that point, Hackett tells Shepard that the Alliance and few other species have being repairing the Ilos archives just in case the reapers were to win. He tells Shepard that they can freeze up one thousand people to be woken up sometime in the future to alert the new species of what to expect and maybe find a way to build the crucible and have it destroy the reapers. Shepard takes crew and ship to Ilos. Edi will guard the SR1 and wake everyone up after x amount of time.

Another way to continue Shepard's story is the reapers themselves. The thing did say that everything can be rebuilt, if destroy is chosen. Could that mean the reapers as well? What if a group decides to do that. They call themselves the Reaper Cult or Cult of the Reaper. The Alliance and Shepard don't want that to happen, so Shepard is sent to find more information about that and try to prevent the group from rebuilding any reaper.

I'm assuming Liara tells somebody other than Shepard about her project, given that her own life is theoretically on the line any time she accompanies Shepard on any of their missions. (Well, maybe not the Geth Consensus one.) She has to be making some contingency for her work to survive in the event that she herself doesn't, whether it's been shared with a few trusted operatives from her network or Glyph has standing orders to pass the information along to somebody else.

Me personally, I think they should've set it up for Liara to get pregnant by Shepard, and set her up as a playable character if they decide to create a sequel after ME3. (Not a main character)

I prefer Liara was killed off and the recordings in MEA were her final words.