Some parts are left open ended like Luke asking for the Professors help at the end of unwound future. Or Descole or Emmy's lives after they left on moments like that with them hinting that Emmy may make a return.
And then now after beating Azran Legacy...the game ends on a to be continued. And they wouldn't have done that for the first they made ages ago. So either they are making a new one with Luke or someone as the new protagonest or they are (And this would probably not be the case since the series isnt even that old.) remaking the first three.
The Unwound Future question, I haven't played that game in awhile so I don't remember exactly what happened post-credits other than Luke and his family moving.
As for the Azran Legacy TBC, they did that as a loop to Curious Village. The order of events goes: Last Specter, Miracle Mask, Azran Legacy, Curious Village, Diabolical Box, Unwound Future. The second trilogy is a prequel to the first.
Unless they make a third trilogy to take off after the events of Unwound Future, I honestly don't think they will be making more Professor Layton games. This is just my opinion though, so if anyone as any proof to prove me wrong...
See I remember them saying in an interview they hinted that they might do something like the games but with a different protagonist. Though this was during the development of Azran but it was after saying it was Layton's last game as the protagonist, so maybe something around Luke?
I dont really care either way but at the same time I don't see why the need to put a TBC for something most know as the first of the series. Much less a very old game that you would go on ebay to get. Not to mention them not giving up on the series itself (Though I question this new spinoff which looks terrible) but again maybe there will be something with Luke? It was kind of open ended in the end.
They did say this is the last game with Layton as the main character but it leave it open for others like Emmy or again, Luke.
Well they put the TBC at the end because, well it was the most logical thing to do. It's not the end of the series (chronologically), simply the end of the game. And since one can play the games out of order, they linked it back to Curious Village to tell those who haven't played all the games/new gamers that "Hey, the first game we released is actually set after this game!".
What does the new spinoff look like? Frankly I'd LOVE another Layton Brothers, even if it's for iOS again.
As for the article, eh. I suppose, yet the way you phrased your question is that there was another game in the main line. There's a difference between "successor" and "spritual successor". What the article talks about seems to be the latter.
We will never know what comes after the Lost Future aka The Unwound Future, sorry im European. But After Lost Future, it says "To Be COntinued" Level-5 does need to make a 3rd Trilogy, because the crossover has confused me aswell. Plus maybe i agree that Luke may be the Protagonist, because in the news they said Azran Legacy will be the Final Professor Layton Game in the Series or that Layton would be switched to another person, and that may be Luke Triton.