I uploaded vertical video for test purposes and it did n`t give me and GIF but squeezed bunch of screenshots (100s?). I tried again and it was the same. Also, I tried to input video dimienssion the other way around, but it reset to original, not allowing me to do it. So, GIF fails in my test.
Video editing on Windows is sort of complicated, mostly when comes to cuts. The only easy thing is cut from the side as every simple app on phone can do.