Hi Liane,
your nickname tells me that you are used to working hard
I do not know, how good you really are, but the range from 2nd kyu aikidoka, I have seen range from "I wanted to help him on a simple technique, before I noticed, he holds a 2nd kyu" up to "Not a Dan only due to formal restrictions".
So I guess you will find yourself well in between. Just trust your sensei. If he really made a mistake, the only effect is that you will take longer from 2nd kyu to shodan, nothing else.
Some organisations have formal restriction, which do not allow that procedure. Only if you feel that you are missing "test experience" you might ask your sensei to arrange a formal test, as for ikkyu and shodan there would be other test environments and you might like to get used to that.
From my side just
CONGRATULATIONS !!!
