It has not been approved yet, but they agreed to do it.
https://arstechnica.com/tech-policy/...t-and-verizon/
If successful, the merger would create a big #3 cell carrier in the US, only slightly behind existing giants AT&T and Verizon.
TMobile was always a cheaper option, but their customer service sucked, and their network often isn't very good in rural areas. This merger should improve that, but it's unclear what will happen after this merger.
Personally I hate TMobile. While AT&T and Verizon definitely have their customer service problems, they pale in comparison to TMobile, which basically tells you to eat shit if you have any complaints.