Microsoft removed support for Skype on TV, not Samsung.
Most apps get removed because the people writing them don't want to support them anymore. The Samsung framework from 2013 was always trouble and it doesn't support many current W3C features that you'd want as a developer. Most people I know are drawing the line at supporting 2014 or 2016 Samsung devices.
Could Samsung update their devices to ensure they still supported modern frameworks? Possibly, but they don't really get any revenue from providing OS upgrades and those devices suck in terms of RAM and CPU.
Most apps get removed because the people writing them don't want to support them anymore. The Samsung framework from 2013 was always trouble and it doesn't support many current W3C features that you'd want as a developer. Most people I know are drawing the line at supporting 2014 or 2016 Samsung devices.
Could Samsung update their devices to ensure they still supported modern frameworks? Possibly, but they don't really get any revenue from providing OS upgrades and those devices suck in terms of RAM and CPU.