Thanks for the comment stinky. However, your assumption, though a fair expectation, is not ‘safe’.
Vulkan does not define any event for presentation->waitSemaphore availability, only presentation->image availability.
You may be able slip by with your assumption, but there is no guarantees as of Vulkan 1.3, and you should instead rely on the vkAcquireNextImageKHR fence parameter where the signaled fence guarantees semaphore availability.
If you have any more questions, feel free to ask. I love answering your questions. Just ask me your hard ones next time. (: