Yeah, Glock has been pretty bad at "big announcements". If I recall correctly gen 5 and the g43 just kind of leaked and dribbled out.
The hyped announcements where the g42, and glock website nonsense.
Some might disagree but I'd say the S&W shield was the straw that made Glock decide to making the 42 and 43. And of course the 1yM line developed into the Gen 5.
As far as a carbine e that has been such a running joke for so long I'd be surprised if they did it this far into it. but we'll find out in a few days