First, let me answer the OP question, so I don't appear rude: Yes, there is a very good chance that a flagship will be announced on 1/21. (Hindsight being what it is and all, I can be rather confident with that statement.) LOL
No, on to more serious things discussed in the thread.
Folks, Verizon isn't the only one that has been selling down the stock of Lumias. So has AT&T, if you read around the forums you'll see it.
I've been stating that for quite some time, and that the reason is that MS knows they are getting ready to release new flagships soon. I knew that the way they were handling the stocks, and the way that businesses are run, that the new flagships were going to be so awesome that no one would want to buy what they have in stock now, so the only choice was to stop production and sell out the stock so they aren't left with any when the new ones come out.
It was hinted that you may want to wait on the new flagship for WIndows 10 to be able to take advantage of all the new features of Windows 10. That means hardware that doesn't currently exist on any Windows Phone 8.1 device, period. Possibly fingerprint scanner? Possibly hardware USB hub that will allow OTG? I really don't know, but I get the feeling it will be more than one hardware feature to make it worth your wait. I don't know what it will be exactly, but I feel quite certain that people are going to be impressed with it for a change.