I'm fairly ignorant as to whether Motorola, as a company, will make a good steward for this kind of arrangement.

Does anybody have any inside baseball to share in terms of whether we can trust this arrangement to last longer than, say, a year?

Not sure they've ever done anything like this, so time will tell.

I do know Motorola seems to not care much about software - they were still shipping 32 bit until embarrassingly recently, and are known for rarely updating their devices. From that lens, this could be a rather symbiotic relationship if it proves it can sell.