canada
The most analogous offence to "witness and/or jury intimidation" is known as "intimidation of a justice system participant", codified at Criminal Code, s. 423.1(1)(b)
No person shall, without lawful authority, engage in any conduct with the intent to provoke a state of fear in ... a justice system participant or military justice system participant in order to impede him or her in the performance of his or her duties
Central to this offence are: (1) the intent to provoke a state of fear; and (2) the purpose of impeding the justice system participant in their performance of their duties in the justice system.
Actions that have been found to be intended to provoke a state of fear tend to be violence or threats of violence, harassment, damage to property, stalking behaviour, etc.
I have searched for and found no reported judgment wherein a person was prosectued with this offence for what they have said while being examined as a witness. One reason may simply be because the counsel and the court would not allow such a response to a question.
But moreso, the example statements you give do not appear to me to be in the category of things caught by this offence. Instead of having the purpose of impeding the duties, they implore others to follow their duties. They also are quite unlike the acts that have been recognized to have the intent of provoking fear: these are not threats of violence or damage to property, not harrassment, not stalking, etc.