I remember all those people, Yours Truly, most were my friends too. Sadly, times change and people move on, sometimes for the good and sometimes not. Sadly, DangerousDan died a few years back, I don't know much how the others are doing but my prayers include them all. I don't know your name back then (you could PM me if you want, or not if you don't), but I am glad you came back to work on some painful issues.
You asked me if it was right to not respond, this is entirely up to you of course. Personally, I have found with some relationships in my life it was good for me to wish them well and then move on. Responding in anger, blame, shame, or any other negative motive does US more harm than them. They are incapable of remorse.
No response is okay, response is okay, just maybe examine your motives and how what you choose to do will affect you.
Leaving in peace is often what serves us well. Forgiveness is also about us, read my signature, that's how I feel.
You are not what your past would define you to be, you are a vibrant smart human being worthy of love and a happy life. Live it, find the joy, embrace the new freedom and enjoy every day.
Hugs