Why does gitlabs terms and contitions mention something about payment?

I supposed it.
My main problem is: why I can’t be sure of it by reading “Terms of Use”. I must understand something absolutely wrongly. The same I had with GitHub. I understood those terms of use as “We don’t charge now but we can change our mind at any time.” Somewhere close to the end of rules (I was asked to read before registering) there were something like that.