Consensus, or un-consensus, I meant.
Additionally, purposes of forks/ upgrades are important.

If upgrade comes from original core team with totally consensus, it should be called as upgrade.
Instead, if upgrade results in un-consensus, and the original core team or community divide into several parts with different visions and plans for developments after the update, it should be called fork.

If you keep your stance like this, what do you call projects used source codes of ETH to create their coins.
There are already so many coins like this, and will appear more later.

Of course, it is a open discussion, I will listen to all your opinion.