Yep. There is no being nice in the business of copyright. But to be fair, they’ve owned the original base game assets.

Not to mention it’s a reverse engineered version of the base game.

They legally own the assets. Taking them off Steam if the title is no longer abandoned by the publisher is a 100% reasonable decision, so you need to understand this is above and beyond what the publisher needs to do.

An outcome like this more than likely means the folks working on the rerelease are fans of OpenTTD and worked internally to protect it.