1) The cosmic microwave background is, in short, the light still traveling from an early stage in the big bang when the universe turned transparent (380,000 years after the big bang, when the universe became cool enough to form hydrogen atoms)
You can see the big bang happening. So when would you say this phase transition to transparency happened? Here you would say it happened 13.5 billion years ago. At the source of the CMB photons you can see, you would say that is happening now.
With that language construct you have an event which happened across the universe simultaneously happening both 13.5 billion years ago AND right now, depending on location. Which, I think, is absurd.
2) Talking to an astronaut on Mars. Mars is between 3 and 22 light-minutes away. If you want to say hello to your Martian friend, it will take between 6 and 45 minutes for your radio to play the sound of your friend saying hello in response.
What is happening while you are waiting for the response? (how do you discuss the time, what "now" means) To your friend your message has "not happened yet" while to you it already happened.
It is silly to have a definition of "to be" that must ignore the practicalities of simultaneous events which involve non-trivial light transit time. It is very easy to talk about a "now" where both Earth and Mars have the same timeline dispensing with the light cone and talking about light travel taking time. It is not so easy the other way around.