To tell the true I think it's a joke... It must be a joke:
First thing first it would be unalligned with what they've always said about security of their system, they simply cannot be scared that one day in the future a stable CF could run onto a PS3 cause they knows well how difficut it's the whole thing to be made.
On a second line if, a big IF,one day it will be possible, probably the life of the PS3 will already be at her last or really near at her end, it makes no much sense to throw out the sword at that point, probably PS4 will be already out when this could seemingly happen, it would make a little sense to fight for an extinguishing business instead of pumping up the new one.
As a third line they've already spoken about a 3.20, not 3.21 or 3.22 or whatelse, they could have integrated those features into the upcoming 3.20, no need to slide the version number, furthermore 3.20 we know it exists.
We can add that doing this they could risk a class action only to stop users from benefit the OtherOS while, obviously, no one working on a ipothetical CF project will do the upgrade saving the chance to work on it and if this will lead to success nothing could stop a CF from being installed on every machine regardless the option to install an OtherOS or not will be kept ?
Finally the release date, 1st April... a well known date for jokes.
The hugeness of games make by itself things really difficult, P2P networks are nearly dead, online reviews and avaliablity of demos have punched a lot the need to "try" games on a parallel way, we can say that PS3 were succesful at defeating piracy, thanks to an improved market transparency as well...
..it would be a completely meaningless move, I don't believe it could be real... if they don't drug themselves, obviously...