Yi Attackspeed slow

Hello, i would like to ask if PBE Yi is/will be immune to AS slows? http://forums.na.leagueoflegends.com/board/showthread.php?p=42117433#42117433 Pwyff said that

Now all attack speed slows can be cleansed and are treated like movement speed slows.

So that sounds like Yi is going to be immune AS slows in general. Also, will Boots of swiftness now reduce the effectiveness of AS slows?

Of course i mean only in Highlander