They suppressed Trump’s account before the election…
That fact was public knowledge.
Did the twitter files reveal anything more specific about why they suppressed Trump's account?
It seems to me that merely calling them "Twitter files" is very effective at evoking and implying possibly more than what they actually contain.
Which I think is the standard definition - suggesting Twitter have made up their own is a bit snarky?
If by "suppressed" you mean "suspended for repeated violations of ToS even though they'd protected him for months by saying he was POTUS and therefore newsworthy and should be granted much more leeway than other accounts", sure.