Did not follow company’s work culture

Currently as a software engineer, our company’s policy is to talk/share issues via threads on slack so that the entire team engineering can see it. I personally like to talk over a google meet if facing any doubts as it’s a very quick and effective way rather than making threads and tagging people to get answer which takes time. Manager gave a warning and said don’t talk in dm and only in public channel so others can see but I violated this law by mistake and she wants to take this to upper authority by tagging senior engineer. This can lead to my termination. I accept that I did wrong, is this an issue for escalation ?