See the previous Q drops that use this expression: https://qagg.news/?q=remember+your+oath

It's an expression Q uses to send a message when there is danger of someone potentially following an unconstitutional order, disobeying the chain of command, or to encourage testimony from someone who has information about "enemies foreign or domestic" that they need to formally report (not doing so would effectively be betraying their oath – failing to protect their country).

It's not something that needs to be 'reminded' to loyal (digital) soldiers who are serving admirably.

See also Q drops re: "You have a choice. Do what is right." which is another way Q conveys this same message.