Rockpool shipshape has been slow coming, true, but it's more the other way around, hardware production ramping up for the launch has allowed more time to fine tune the software.
I don't know the timeline involved but the various modules are still in production so that Flotilla can hit retail without being out of stock within a couple of days (and requiring 100% capacity to restock immediately, which would be inadequate, everything else like Picades, HATs and pHAT are in high demand themselves and need to be topped up regularly too).