I think that maybe echnically it could be possible and probably smart people already did that.. But it depends on the actual HW, if it has an ARM SoC and runs Android/Linux already, in principle you could port something like LineageOS like you would do to a phone. But shit could hit the fan when we're talking hw support: bootloader unlocking, kernel/device tree, GPU/display drivers, audio, touchscreen, Bluetooth/Wi-Fi etc I highly doubt that manufactures feel like sharing their stuff and dumping all the blobs of all the hw it's a project on it's own.