Wouldn't suprise me. A woodworking channel I watch had all of its videos deleted with no warning. The channel owner said that customer support told him it's against their policy to say why videos are deleted.
At YouTube's scale it's almost impossible to not mess up these kind of things some of the time, that's okay. The unforgiving part is that they just don't care.
[1] https://en.wikipedia.org/wiki/Weapons_of_Math_Destruction