This is not correct.
If you compile GPL licensed code and distribute the binaries, you are still obligated to make that source available under the same license, with your changes.
In the case of GPL, but not all open source licenses, this even applies if you link to (compile with) the GPL code from your own. The MIT license on the other hand, comes with almost no obligations.
What RedHat and others do is add support, services, and their own proprietary programs on top of the open source. The open source parts of that distro is and always will be free as in both beer and speech.
The non-free packages are often distributed via separate repositories to make the distinction clear.
That is just one way to fund open source software and is sometimes referred to as the RedHat model.
What OP is asking about is the donation model to fund software. You’re not required to donate, but if you enjoy the software and you can afford it, then there is your opportunity to give back.
As someone else pointed out, hosting and bandwidth isn’t free, so it’s important for these projects to find some revenue stream to pay for that.
Instead of calling tech support they should have checked on expertsexchange.com first.