AFAIK, the main problem with NetAtmo intervals is not that it would not be able to send more often, it is because the wifi would drain the battery immediately if it was sending data every 2s. It aggregates data and then sends them off at longer intervals.
So, either WeatherFlow will use a different technology, or the battery life will be close to useless. I didnt check which one is correct
Believe it or not, I read somewhere that NetFlow's wireless chipset not delivering on the manufacturer's claimed power draw was the reason why they scrapped the first test batch of units back in December. I also seem to recall that they were going to make the polling/transmit interval a configuration option, so that each user could pick their tradeoff between battery life and data frequency.
One of the reasons why they decided to add the *free* hub device after the campaign closed is so that they could offload the web/API server functionality to a device powered by wall/mains power. Campaign backers PUSHED for local API access, so that this project didn't turn into another Netatmo. They also pushed for external/solar power options for the Sky (wind) unit, so I guess that you could say that they're using a "different" technology to work around battery life concerns.
My only personal concern is the accuracy of the haptic rain sensor, which is why I have an Acu-Rite tipping bucket unit disassembled on my workbench today so that I can retrofit a NodeMCU for logging rainfall from an alternate source for comparison. I also suspect that sleet/hail will wreak havoc on the haptic sensor's readings, but an un-heated tipping bucket isn't much more useful with frozen precipitation.....