Historically, smartthings has relied on OEMs to manufacture the SmartThings-branded devices.
The ADT SmartThings dual logo motion sensor, for example, was manufactured by Nortek. But I have no idea who holds the rights to it, I don’t think the Samsung/ADT agreements were ever released publicly.
Also, looking at this comparison between scout alarm vs adt integration, has anything gotten better with the scout alarm option
Nothing has changed except that smartthings stopped actively marketing it to their customers once they had the ADT arrangement.
It’s still listed in the official knowledgebase, but that’s about it:
https://support.smartthings.com/hc/en-us/categories/200058800-Guide-to-SmartThings