Update summoner spell Cleanse for clarity please

I just finished a game where I, as was playing against a . Im no stranger to Malz as a champion as ive seen him in action before, but this time I figured id try and counter his ult by bringing summoner spell . It was a choice specifically to counter Malz (or so I thought) because no one on the other team had any real reliable hard CC threat that I had to worry about.

So Malz hits 6 right around the time I notice the enemy coming to gank me, so I promptly flash away towards my turret only for the malz (who flashed at what I thought was the same time) to land his ult despite my champion being WAY outside of its cast range (I understand this is just because of latency or w/e). I think ill be fine though, I was sitting around 60-70% and all he landed was his ult, so I could cleanse it and turn the Kha's tower dive around for a kill! I gleefully press clease and start to line up my rotation only to realize im still CC'd. Im frantically spamming hoping that maybe I missed the button or something but to my horror, I begin to realize that despite the spells description reading "Removes all disables", it does not in fact remove a ult.

So now im sitting in a game with only one summoner spell because that I took to counter Malz and only Malz is completely worthless. Luckily the two early kills I ended up giving to Malz didn't matter in the long run because my bot lane did extremely well and carried, but the entire event was nonetheless frustrating to deal with.

TL;DR: I think it would be nice if Riot updated summoner spell to better clarify what it does and does not remove. In terms of the word "disables" used in its description, it should by all accounts remove a ult since it does in fact disable my champion.