Yes it is. It's a flaw that naehrwert is attempting to exploit. We've been discussing it for the past few hours.
Nonetheless, it's a IOSU userland flaw only at the moment. It should be more relevant if it's possible to attack the kernel with it.
The flaw itself was patched after 5.2.0, so, the general rule applies, if you're on a low firmware already, don't update. If you have already updated then don't worry about it.
You're not missing out anything if you updated your console, this is just a warning for those who still are on a low firmware version. By not updating you will have access to more attack vectors in the future.
The plan is still to provide a full exploit that works up to the latest firmware (that means IOSU userland and kernel access up to 5.5.0).