The list of snaps is downloaded once a day. If the snap came out that very same day, it won’t be in the list!
Before we used to query the store directly, but that was too slow, which is why we’re doing it this way now.
We could look at making the window smaller, though that would use more bandwidth and might pummel the server a bit. What do you think?
For what it’s worth my current position is that once a day is a reasonable trade-off – if you try to install something on the day it’s made public, presumably you’ll know the name of the thing so while slightly less convenient it shouldn’t block you.