New units on EB2: What are most likely to be included?

[Moros]

Palmyra and nabatae had hellenic influenses so that would probably mean some heavier cavalry and infantry units in these provinces, although not expecting anything along the lines of 200 AD clibinarii, also did either them employ pike-phalanxes?

We indeed have a palmyran unit planned and a few more generic northern bedouin units. Some which are based on nabataean and other tribes/nations of the regions. Possibly the best arab cavalry will come from the east though.
On phalanxes: no, no evidence or anything that suggests the use of phalanxes by the factions of that area that don't have hellenistic roots. There was hellenistic and Roman influence in the region, especially in the Hasmonean (see 1QM/1Q33, 4QM from the deadsea scrolls) and Nabatean kingdoms (see Petra) at the very end of our timeframe. But those infantry units were more thureophoroi in style. Most information on Palmyran infantry dates back to a few centuries after our time frame. These seem mainly Roman and Parthian influenced though some typical arab traditions seem to be kept as well, such as small round shields for example.