I'm not starting this to discuss the previous episodes this season (although we of course can and the Alex thing was predictable from the start considering this is the CW) but to talk about a future episode. Episode 8 is the "Crisis on Earth-X" crossover, episode 9 doesn't have a title release yet. And episode 10 is titled Legion of Super Heroes.
It's about damn time. They have been teasing this since Flash season 2.