BuzzR, welcome back!
The details of the recall can be found at the links
in this post from earlier today.
Short version, the valve springs in some Subaru engines were found not to meet engineering specifications and a recall was issued.
The engine in the BRZ has a gasket seal that has to be reapplied very precisely in the process of doing this job. Some mechanics have not done so and that has resulted in a small number of engine failures due to oil starvation. Most were repaired or replaced with no pushback, some were more difficult.
The general thought even for those of us that had successful updates is that if we had to do it over again, we probably would not do it. The recall covers damage if it does fail before.
As said above, check your VIN at at the appropriate site to see if its required.