Nobody can say if things would have turned out differently.

You mentioned he's known for running late, maybe he lost track of time before seeing your nevermind message.

I highly doubt it had anything to do with not being dressed on time, since he asked if u needed more time.

In the same breath I highly doubt it had anything to do with you wanting to meet in the evening, he could've just explained why that didn't suite him, or agree to reschedule.

But your nevermind message?

That was just plain rude. I wouldn't respond to a text like that either, neither would my bf.

I agree with divine, the whole interaction and your reaction as well (nevermind and then getting into your pajamas) is all weird.
Not just him. If you were seeing each other for three years, one would expect a higher level of communication, or in the very least be on the same page and not question motives and meanings months later. And like poster above mentioned, worry for his safety.... In your shoes I would've texted one if my bf's friends to make sure he was alive.

Sorry to say, but sometimes we don't get closure, we have to make our own. Closure is a dream movies and books sell us, real life doesn't always work that way.

Maybe you should just accept that this is how it turned out and that you can't change it.
Let that be your closure.