Up until a few years ago, Lionel had a Club Car section on their website. When they redesigned their site a few years ago, the Club Car section was not part of the new design.
Like you, I wish there was an easier way to find out about uncataloged items. For example, I had no clue about the Legacy Station CofG engines until you posted above.
Yes, METCA just announced a couple of LionChief+2.0 GG1's. Let me just say … but wait, there's more. Maybe METCA, maybe TCA National, maybe both; we should know in a week or two.
I would love for this thread that you started to serve as a point of reference for us all to inform each other about uncataloged items that are being made in connection with the 2019 catalog(s). Below I've pasted some images of locomotives that METCA is doing. I will update when other things in the pipeline are ready for official announcement.
Only 1 Susquehanna SD40-2 remains unreserved.