This observation is so obvious it's banal; I don't mean to be offensive, but it's a truism in the same way that, "If you don't like an edition of D&D, you don't have to play it," or "If you think the latest AP is terrible, don't buy it" is accurate.
Yes, of course the only thing that matters is what happens at your table. WoTC can pump out every Paladin in the world, and that's not going to matter to me.

That's not really what most of us are discussing, however.
There are two different issues-
1. What is Greyhawk? On other words, why bother? For example, if someone said, "Hey, I love Dark Sun." And you said, "Great, they are going to publish a Dark Sun 5e. Except ... it's just going to use all the base rules. It will just have a few place names and stuff. Oh, and it will take place on a giant ocean filled with vampiric squid...." I'm guessing you'd question that, right? Or if the Eberron book was published, and they decided to make Eberron a world of low- to no-magic?
So, yes, of course people can do whatever they want in their home campaign. But there has to be some reason to publish Greyhawk. It's not like people are clamoring for another generic, flavor-less setting. We already have the FR.
2. The "home campaign" argument cuts both ways. If they release the Swords & Sorcery, humanocentric, 1983 reset Greyhawk without Dragonborn (for instance) ... guess what? No one is stopping you from putting them into your own home campaign. Because that's your canon.
See how it works? In fact, that's what made so many varieties of Greyhawk amazing! People would take that base skeleton of Greyhawk and add their OWN flourishes, instead of demanding that it be placed into the "canonical" Greyhawk.
Which, to be honest, is a much better way of doing it. I really don't want to see Greyhawk spellplaguesundered. Because that's the core of it- DIY. Give us the very basic stuff, and let a million Greyhawks flourish. But that doesn't happen when WoTC has to force-feed us all the changes just to keep up with whatever silly rules they want to introduce this year (and/or takeaway the next).