I think GP meant people who actually have reasons to be offended, like their ancestors having been actual slaves to actual masters.

Almost everybody has ancestors that were enslaved. E.g. most Germanic people where enslaved by other Germanic people, or the Romans at some point in time. The only question is how far back you have to look and how far back you can look.

Thing is... nobody really has a valid reason to be offended. In this case context matters and the English language is an evolving construct.

Isn't this what the article was criticizing in the first place? A bunch of white people pretending to care by doing a meaningless change?

But again these are all white people, you see?

When you think about masters/slaves, do you think about black people only? If so, why?

There are countless examples in the history of the world about slaves, including different ethnics, in every continent. May they have a word on this issue too?

Throughout history, various races struggled from slavery, pretty much the entire spectrum is fully covered across the world. Nowadays there are more people in slavery than at any given time before.

It's not a coincidence that "Slav" and "Slave" sound so similar. And Slavic people are quite white indeed.

Exactly. Unfortunately for many Americans history stops in the last century and at the geographical borders of the USA.

Slavery in Russian empire was de jure abolished about the same time as slavery in US. Not surprisingly, it took even more time for "de facto" changes to happen with various restrictions still being a thing into 1970ies. If anything, kolhoz system was anything but slavery with the government being ultimate owner.