That's not even the half of it. After years and years to litigate what's official and what's unofficial, what was the President immune from and what wasn't he immune from --- it'll all end up back with SCOTUS.
And when that day comes, SCOTUS will decide everything in Trump's favor*, granting him total immunity from everything. It didn't have to issue that ruling today. It merely had to remand to the lower court to start another merry-go-round of litigation.
*Unless the Dems will have dismantled this iteration of SCOTUS by then, or unless Trump wins in November, killing the entire litigation by himself and rendering further judicial review of this matter as moot or unnecessary.