It is a common practice, tbh. Few projects I've participated in did this routinely - that is it, relying on something to be fixed later as development progresses. If games were done as some people suggest here, "technology first, game design after", many couldn't be delivered as you still need time to iterate, to test things working gameplay-wise and so on.Something like that....In short they relying that new "tech"and all necessary net-fixes will arrive somewhere during their development......
Flight model as one of the examples for me. CIG ignored it completely, which looked strange to me, then found the right person(s), assigned them to this sub-project and fixed the stuff. And it looks and feels 'proper' now.
Downside of this is that you never can deliver in time as there are too much inter-dependencies between this 'to be' fixes. Well, most of the time technology is 'not there' so there is no other way besides go and develop things.