Do you have an estimated time this will be out? For the default nodebb theme at the least as we don't currently use a custom theme.
As a side question, I know you can manipulate web pages with JS/JQuery but I dont use them, Would we be able to use JS/JQuery to modify the dropdown list in the user settings and remove specific dropdown items from the skins dropdown? This would perhaps work as a temporary solution.
Edit: Ignore the above,I found the JS to hide them.
Note For Others: You can use code below to hide specific skins from the dropdown menu
$("#bootswatchSkin option[value='cosmo']").remove();