Apple has released a small update to version 16.3.1, but only for the HomePod. The description only talks about minor improvements. Perhaps it only contains adjustments for the HomePod 2, but possibly also improvements for the upcoming new smart home architecture. This had to be withdrawn at the first attempt due to serious bugs.
At best, the increased update cycle for the HomePod could be a sign that Apple is taking the home ecosystem a bit more seriously. The upgrade to Matter will soon introduce a cross-manufacturer standard that should make digital life at home easier.