The big difference between OSTC and Frog is that the first one is open source. Even if they discontinue it, some skilled people might be able to release a firmware. Frog was not open source therefore the upgrade options were limited only to the manufacturer.
I don't think it is necessarily a question of target audience (althought it pushes customer service to be more reactive or proactive). Some non-tek computers from other brands gets updates as long as they are manufactured. Whenever the OSTC will substantially change from previous versions, like everything, official updates are likely to end at some point. I might be wrong but it doesn't seem to me that the OSTC mk1 still gets update