You know what this is.
Sony has released another firmware update for the PS4, version 5.53-01. But while the nomenclature for this firmware update is unusual—Sony has never yet launched a firmware update that is numbered or named quite like this—it’s not actually doing anything new. On the user-facing end, it’s not doing anything at all.
It is, in fact, another one of those famed stability updates. Basically, I assume some as of now undetected security holes in the system’s OS have been patched up, and some glitches have been smoothed out, but there should be no visible change to your experience using the console whatsoever.
The next major update for the PS4, version 6.00, will presumably be launching later this year (Sony usually launches major version number updates in Fall). Until then, I suppose we must all brace ourselves for stability updates—assuming wise even get any to begin with, that is (which we might not).