There are approximately 1.67 billion Skype users world wide *. 2017 when the thread was created, there's only 183 people that identified they had the same question. Putting on my pragmatic hat here for a moment, since the 23rd of Nov. I see that Microsoft has been ignoring the same question from many I don't know that this happened, but I've seen similar in my own experience.
Speaking from a perspective of been a Product Manager for both hardware and software, it's entirely plausible there were folks who removed the icons from the status bar only to complain to Microsoft that they needed a way to know if they were 'Away' when they didn't mean to be. More importantly, it shows whether you have connectivity or not. It appears (IMO) that this is a design decision by Microsoft because their Menu Bar does more than just give you access to sub-menu items the icon(s) displays status like 'Away', 'Do Not Disturb' or 'Invisible'. I use both OneDrive and Skype, both have animated icons and neither can be removed from the Menu Bar.
This indicates that there is no static icon file that you can edit or delete. These icons appear to be rendered (on the fly) as they are animated.
