We still don't know the price of the device. I think this device has to really target a low, potentially subsidized, price point in order to be worth it over existing handheld devices capable of streaming (or even running games locally), and if that's the case, it may suffer from the Amazon Fire problem of being incredibly locked down and not seeing as large a development community as would be necessary to achieve a "no restrictions" Android setup. If Sony is subsidizing the device, they would really prefer it if consumers stay within their media ecosystem rather than having the ability to go out and use and/or pay for services that don't allow Sony to recuperate their losses.
It is also possible that the device seen here is just running Android for testing purposes, and the final device will ship with something more locked-down. This seems unlikely due to being far more effort than just using common tablet hardware and shipping Android, but Sony may prefer to do that to achieve more control over the device.
I basically see this going in 1 of three directions:
a) Sony will deliver the Q Lite as is, in this form - a barely unmodified Android (13?) Tablet handheld that presumably has Remote Play and PS+ preinstalled. I find this very unlikely, but probably the best case scenario to maximizing value/minimizing e-waste of this device.
b) Sony will deliver a heavily modified/locked down version of Android dedicated to a PS5 aesthetic/UX that only uses Remote Play/PS+. I find this the most likely option from a matter of cost and practicality. Android is extremely competent at scaling to various form factors and has 1.5 decades+ of application and hardware support. Other than embedded Linux (yes I know the kernel, shush) it's one of, if not the easiest OSes to build up from, especially if you are running Qualcomm, which they are rumored to be in a partnership with. This will make things more difficult to modify/hack though.
c) Sony will ship a completely different, restricted scope OS likely based on a cut down Linux or variant of their PS4/5 BSD-derived Orbis OS. This is less likely than the modified Android, but far more likely than the naked Android tablet shown above. It would fit the branding and ethos that Playstation tries to exude and probably increase the difficulty of hacking even higher, but the design of this device does not strike me as being in the scope/budget of porting over their console OS to mobile ARM hardware. They are very clear about this being a companion device, likely just to test the waters of making handhelds again, with a lower scale target to reach (video and input streaming) than actually including another power target for their entire platform SDK (committing to a Switch style platform halfway through the console cycle or adding the equivalent of a PS Vita in an era of developers barely being able to target 1 console SKU competently, let alone 2).