On Bluetooth, the device is discoverable by MAC address due to beacons it outputs, even if you don’t have a name attached because the device isn’t in discoverable mode the MAC is typically sufficient to make a educated guess as to what device it is.

On WiFi, stations are constantly outputting packets as well with their MAC and associated AP broadcast. A WiFi card operating in promiscuous mode(aka monitor mode) is able to receive, interpret, and log these packets, allowing individuals to additionally determine not only that the station exists and its MAC address which can similarly be used to make an educated guess as to the device it is representative of is, but also the access point it is connected to, allowing an individual to increase certainty as to the geographic location of the device via triangulation(which can be done with a single moving device with GPS and WiFi, an Android phone works for example).

I would not call the OPs concerns unfounded just like I would not call someone’s concern about putting a sign out front their home that says “I have a expensive power station inside here”, as the only difference is the minimal skill required to do such determination as compared to simply reading a signs, but the effort would be minimal: a OUI lookup tool, a stock Android phone running WiGLE, and any computer with a WiFi card that runs an ARM or x86 architecture(I.e. raspberry pi, a old laptop, etc.) or even substituting the computer with instead using a Android phone with custom ROM and kernel to enable monitor mode on a USB-OTG connected WiFi adapter. The only prerequisite to all of this is some google searches, owning or obtaining the hardware, and following step by step instructions online.

With that said, will there be a high likelihood? No, but there’s also not really a high likelihood your stove will catch fire if you leave it on while you sleep, but people get out of bed to check and turn them off anyways, don’t they?