The wireless module is top-left on the PCB (below the cut-out). I can't see the model markings on the chip, but the Realtek "Crab" is visible and that explains the lack of WiFi probing on the device. It's an older Realtek chip not supported in the upstream kernel (because if it was, it would probe) and LE does not add Realtek vendor drivers as they're a pain in the rear to maintain over time. They do exist though, and you could always self-build an image with the driver embedded. The BT side of the module is serial (not SDIO) and in some cases there is support for the BT part but not WiFi (as they are different drivers) but for that we need to know the specific chip model as the "compatible" string in device-tree determines which driver and how it loads. The photo isn't high-enough resolution to see the model details, and they're often a bit fuzzy to start with.
NB: Logs from a vendor kernel boot (Android or CE) will probably show more clues about WiFi/BT chip details, although the multi-vendor DHD driver that's used in Amlogic kernels does obscure the info a bit.