Just earlier, the Production Director of Call of Duty: Modern Warfare Paul Haile brought us some good news, which is also a feature that has been requested by many PC players - the options to make the CoD:MW game file smaller.
In the tweet, Haile wrote, "tomorrows update will have mode specific uninstall options for PC MW owners."
So, update 1.28 will let PC players uninstall the modes they don't want, to save up some storage space. This also includes the Campaign and Co-op. You can just keep the mode you want and get rid of the rest. The launch file of MW was already big (about 175 GB), and every update before only increased the size. This function has been available to console players for a while, but it's nice to know that PC players now get covered too.
The rest of the features for update 1.28, however, are still unknown.