I think it's one thing if you absolutely know that there is one dish that, to your whole family, absolutely makes the holiday. But once it starts getting more complex than that..well, look at the wide variety of particular items people even here in this thread absolutely desire for their 'ideal' Thanksgiving or Christmas. Are you supposed to ask every person what it is that 'makes' the holiday and make sure they get it? That would be awesome, but not really practical once you get past two or three people.
If you have a gathering with people from different families, probably at least one of them would go home disappointed by that standard. Even if you serve the requisite mashed potatoes, some won't like it because it's not the way they remember it. I do get that food traditions are about memories and feeling connected, not just 'I want my mashed potatoes'. But it seems that traditions are becoming far less universal, so *someone* is likely to be unhappy with *some* aspect of what you've done.
To my mind, the OP *has* incorporated pretty much all the Thanksgiving staples. And doing them 'traditionally' by one standard might not be traditional by another anyway. It wouldn't have occurred to me til this thread that the way things were prepared was considered that universal that it 'wouldn't be Thanksigiving'. Like others have said..I do think if she invited her family over and sprung on them a traditional Italian or Chinese meal, that would be a bit of a shock. But this just doesn't seem that different to me.