Should I reply to the New Year message sent by my colleague who has been awkward before (he may have sent it in groups)?

Of course, I have to reply. A friend is someone who wants to have a heart-to-heart talk. He doesn't forget to bless you when he is at odds. This shows that he has you in his heart. It is also possible that he took this opportunity to make up with you. Think for yourself. Why did the embarrassment between you happen? Is it necessary for friends to hold grudges for life? Give him a generous answer. Maybe after you reply, he will take the initiative to come to you, just like you before, or even better.