I noticed a few of my Whirlpool coinjoins no longer having 5-inputs-5-outputs and instead having more. Turns out Samourai have implemented what they are calling "surge cycles": https://nitter.net/SamouraiDev/status/1658020576491978752
Essentially, if the total fee is more than is needed after selecting the two fee paying pre-mix inputs in order to perform a coinjoin, instead of enrolling three post-mix inputs as usual the coordinator will now enroll additional post-mix inputs. This makes the coinjoin transactions larger and therefore even harder to break, as well as increasing the throughput of remixes meaning everyone gets more free remixes faster, all for no additional cost to the users.
Here are a few such coinjoins from the last couple of hours each with 7-inputs-7-outputs, instead of the usual 5: