I'm fine with the game not featuring Alfendi Layton. The series (which only had one so far) is called "Layton Brothers" where the second son is only mentioned, but not shown in Alfendi's game, Mystery Room. I hope this upcoming game will feature and focus on that other son so we can come full circle with an eventual Avengers-like crossover. I'm surprised they implied that Hershel Layton isn't gone, but may take a sidelines role similar to Mystery Room, and perhaps even more hands-on this time (Hershel is technically unseen, but definitely in Mystery Room for those who haven't played the game). I do wonder if Hershel (assuming this is in Alfendi's timeline) is still working at Gressenheller University? Also would be nice to see Alfendi and Lucy in a cameo role though, perhaps to assist in a case through simulations and interrogations.

And if Scotland Yard is involved, then (again, assuming Alfendi's timeline) I hope Commissioner Barton has a role too.

I am aware that this is being called a Professor Layton game, and not a Layton Brothers game, so there's a very strong possibility that the other brother may not be the protagonist, and we may even get another mobile game for that other series instead, alongside this title.

Either way, I'm interested, but damn... Rest in Peace Akira Tago.

Double posting to bump this thread with an update:

During the Level-5 Vision 2016 event, it's confirmed that the next Layton game is NOT about Hershel Layton's other son, but rather his daughter this time. Scheduled for Spring 2017 in Japan, and a global release later on in 2017 for 3DS, Android, and iOS, the Japanese trailer and website have been launched for the new game, Lady Layton: The Millionaire Ariadone's Conspiracy.

And I got this from an Ace Attorney fansite, because why not?