I'm a product manager working in a big company.
My track consists of two teams trying to build one product. The product is big and that's why we scope it to two different teams.
Our senior product manager left the company and they didn't hire a new one, hoping that one of the two product managers (me and the other one) will be promoted.
To be promoted, you need to work on a project that helps the whole department.
Last year while we were discussing the direction of the product, we had an idea that can benefit many parts of the company.
There was a competition between me and the other product manager about who will lead that idea.
He ultimately could get it by playing it "well". He ignored our main product. His team was suffering from lack of product management. He spent almost all his time preparing for that idea.
Later I was assigned to work with him, but because of the history, he knew more than what I did and the stockholder already knew him. So he was the leader.
Recently the product went live, and everyone in the company is positive about it. He will be promoted soon.
We normally sent a mail thread about updates like this to the whole company.
Will it be silly to congratulate him as a reply to that mail thread? Will I be perceived as someone who is trying to hide his pain?