Gave this some thought the other day, and I think we probably won't hear any more plans about future characters until Annie is added into SG2E, since that's technically the other *half* of the plan to implement a new fighter.
I would bet that once that is done and they have a solid plan and workflow for implementing fighters into both, if they do decide to continue making new fighters they might work on multiple at once (SGM team working on a brand new one, and SG2E working on the one recently introduced in SGM), but I'm betting Annie is a standalone project for now while they figure out how much time and money are needed to make one from start to finish.
I think original announcement said she was planned to be added to SG2E in 2021, but that was before all that business with the mass exodus from Lab Zero and the founding of Future Club, so I'm guessing they'll need some extra time to figure things out and get things settled before they can work on implementing Annie in SG2E.