The preference option to always encode IPTC as unicode seems to be gone. A checkbox to encode as unicode is still found on the Info panel, but not only would that mean having to click it each time you change something, it also doesn't work when you enter your IPTC via e.g., the Stationary Pad. Worse, the checkbox doesn't seem to be working correctly either (at least it looks like it still doesn't encode the IPTC in unicode)
The interesting thing furthermore is that the dropdown selector for the encoding on the Info panel does list unicode as possible encoding, whereas the default encoding that can be set in the preferences does not. This seems like an inconsistency to me too…
I know IPTC is perhaps not the most modern choice and doesn't support all the new fields XMP does, but I still like to maintain it for compatibility reasons. Furthermore, Adobe nicely keeps it in sync with their tools too.