Looks like T-mobile free iPhone XR back to people who missed it during thanksgiving .
https://support.t-mobile.com/docs/DOC-39262
Get a free iPhone XR, 8, or 8 Plus, OR get up to $750 off an iPhone X, XS, or XSMax (after rebate) when you purchase the device at a Costco Warehouse at Full Retail Price (plus tax), add a new line of qualifying voice service on a qualifying voice plan, and trade-in an eligible device.
IF you do it thorough COSTCO you don’t have to go through monthly BILL credits and years of WAITING.
IT SAYS QUALIFYING PLANS – for existing customers please check if your voice-plan is eligible or not
Good for customers who want to add lines .
Pros : good for people who want to get rid of old 6s iphones and above
No monthly bill credits
Cons : New lines / new Customers
Trade-in required
I am not sure if someone who used SIMILAR offer during thanks giving is eligible or not