If I follow your link...
  • The Morning Joe video plays in Safari Technology Preview but there is no audio.
  • Firefox started playing the video. again without the audio, but after several seconds the video was replaced by a request to install Flash video player.
If I go to https://www.msnbc.com and click on the MorningJoe link (https://www.msnbc.com/morning-joe) the MorningJoe episodes play correctly in either Safari or Firefox. I did some further exploration and found that when you add /episodes# to the link the problem arises. Without spending hours troubleshooting MSNBC's code and site design, all I can do is speculate there is some old, out of date, HTML on the site. But in any case the problem is MSNBC's and nothing you can do will correct the problem other than contacting MSNBC's web manager and complaining. In the meantime you may not be able to get to past episodes of MorningJoe.

NOTE:
  • Flash is an EOL (End Of Life) technology and Adobe iwill end all support of Flash on December 31, 2020.
  • The latest release of Safari Technology Preview does not support Flash
  • It is highly likely Flash will not be supported in the next release of Safari
  • Flash has never run on iOS
  • I do not have Flash installed on my computer.



"All you've got to do is own up to your ignorance
honestly, and you'll find people who are eager to
fill your head with information"
--Walt Disney