No news other than there is one coming.
Sometime ...

It's known that Triumph developed a 1500cc then an 1800cc originally for the Rocket.
These engines worked and were running protatypes so the basis is already there.
I for one can't understand why the don't, in effect, lop off one of the Rocket's cylinders and have a stonking 1533cc twin!! Mmmmm

Word got out Honda was developing a 2000cc V and Triumph (being stuborn buggers we Brits can be!) decided they weren't going to be outdone and upped it to 2.3l.