LoRaWAN has a star-of-star topology, meaning that each end-device communicate only with Gateways, which communicate only with central network server.
I did not see in LoRaWan specs that this topology is mandatory, just this
LoRaWAN networks typically are laid out in a star-of-stars topology in which gateways relay messages between end-devices and a central Network Server"
However, the French Wiki page about LoRaWAN, which is much more detailed than the english one, talks about this (translated):
LoRaWAN does not allow direct dialogue between two connected objects. If such a dialogue is to take place, it is done through the application server5. However a study of 2017 led by Konstantin Mikhaylov shows that its activation, if the terminal equipments are close enough, allows to improve their energy consumption by reducing the spreading factor required to receive the data
So, if if end-device-to-end-device commmunication works with your devices, that is good for you, but you do not follow the "guidelines"; there might be some specific communication process between gateways and end-devices to enhance reliability/performance. Maybe you will encounter some problems later (long-term communication reliability, certification issues); maybe not !