Hi Aaron,
Yes, your VFT will be OK outside without watering during rainy season, but that is very risky in hot days.
When sphagnum moss is damp, it gets wet very easily after watering, but if it is dry, it takes time to get damp/wet again, that can be normal for CPs gets toasted in hot days because normal watering may not be enough to wet the moss when the moss is dry. The worst thing is we thought we've already watered the plant but in fact, the water flew out thru the dry moss pretty fast, but the moss is still not thoroughly wet yet. It gets even worse in the next day if it's still a very hot day, end up you have a dried crispy VFT in your garden.
It's always safe to have a tray underneath your VFT (if you are growing it in pure sphagnum moss) because the water will be sucked up the sphagnum slowly after watering, and we don't have to worry about plants being toasted at all.
This was my experience with VFT growing in pure sphagnum moss.