Whether it's Ok or not, is NOT the point. It's a matter of respect.
Do this: Create a Page for your mod/WT/whatever instead of a post, send the link to MB so he can replace the link on the OP. In that page you are free to add your Patreon or whatever. There's probably even a template for that.
Just don't do it in his thread. Just consider how you'd feel if it was the other way around, and someone started posting their Patreon link in your thread.
Also, facepalming anyone that calls you up on perceived mistakes isn't helping your case, you come off as rude and insensitive, even if you may be the sweetest person in the Universe.
Peace