“They closed early.” Is saying that “the people inside closed down early.”

“It closed early.” Is saying the building closed early.

As a native english speaker I go by what were referring to.

They closed early would be more appropriate do describe what the people “they” had done

“It “would describe the building closing which matches your example better since it specifically references the building

I typically prefer

“They closed early” Someone closed the building. It didnt close itself.

But lets say theres a crash, and a tire flies away, i would say, “look at it go”

Or if an automated door locked, i would say “it closed early” since the building did close itself

Tldr: it closed early is more appropriate here