1080p "is"* 2k
Technical stuff aside, yes, there are offical 1080p version, and my recent uploads have them.
* Nk means horizontal resolution is near Nx1000 pixels. Since 3840 is ok to be called 4k, 1920 is ok to be called 2k. NNNp means the vertical resolution is NNN lines (pixels) and is progressive scan (please don't ask what is scanning).
And since they are only considering one dimension, the actual aspect ratio doesn't really matter. (640x480 is 480p, 720x480 is 480p, 854x480 is 480p.)
Now
about half of the some videos are in "vertical format" (1080x1920) so
technically they are "1k" or "1920p" but we are more familiar with 1920x1080 so calling them "2k" or "1080p" we all can understand what it means.
(edit: I got confused mixed up shaggy susu and yesui LOL but whatever)
2560 is 2.5k FFS.

*dying from people calling 2560x1440 2k*