That and Romania wants all of northern Mesopotamia, particularly the areas around and including Mosul and Erbil, to put an end to the Eastern threat by making the area a giant fortress and to be in position to raze the rest of Mesopotamia if the Ottomans, or any other Persian dynasty, gets belligerent. With that done Romania will not have any real threat to its mainland borders and its integrity will be the securest it has been since Justinian if not farther back.
I really hope we see a more transformative border than that. Capturing Mesopotamia in its entirety, and perhaps even as far as Bandar Bushehr/Shiraz. (Shiraz as a client ... state? Would be interesting)
Like, we need a genuine humbling of the Ottomans in the same way Hungary was humbled. Plus, whilst the border is long, as long as the Romans include the right border settlements and fortify the passes of the Zagros, Mesopotamia can be a huge source of revenue (and oil in the future). It also gives another area for a major staging ground for eastern naval affairs. A Mesopotamian fleet based in Basra, Kuwait, Bandar Bushehr gives a pretty sweet expansion of Roman naval ability, and if they can be as successful as getting Kish and Qeshm, then you've made it so that constraining the Roman fleet in the East requires shutting down two major sealanes.
There are other benefits to it too. Georgia will likely expand into the Iranian Plateau in such a war, making them a stronger ally and securing swathes of the border, whilst being the more obvious focus of Persian revanchism vs Turkish revanchism.
It also means that the only eastern frontier left that the Romans need to worry about is the Arabs. When you have two naval staging grounds that surround them, the easy solution is to mix up economic sabotage and clientelisation/occupation.
I wonder, are there ANY Arab Christians at this point? (Anizzah?) Just as it'd be interesting to see a Christian Arab Client State based at Al Hira, and allow it to be the frontier of that conflict. Restoring the Anizzah from the Syrian interior to giving them Al Hira and that frontier could be really interesting.