First of all I would like to address the Seleucids because they seem to be a favorite in this thread. I believe that some people are overestimating the Seleucids ability in this scenario. Unless the Seleucids adopt Persian culture and language, almost immediately they will be hard pressed to keep hold of Iran, which once rebelled the Parthians will swoop in like otl and take it all. Without the vast territory of Iran, they are put on a even playing field with the Ptolemics and Armenia and are at a huge disadvantage against Pontus. Once lossed, I feel like the Seleucids will be unable to retake the east. They will then be put in a war zone between Pontus,Armenia,Ptolemics and Parthia, which I doubt they survive.
As far as Ptolemics go, without Rome they will not have a impossibly powerful foe forcing them into submition, will be significantly more stabile. With the rise of Parthia and Pontus it is possible they take the fight to the Seleucids, however I doubt they gain much.
Maurya and Aksum are most likely unaffected. Except for trading partners in the case of Aksum.
Pontus and Armenia however I believe could be the true winners in this scenario. With an adopted Greek culture and language Pontus is set to dominate the Hellenic world like otl if it wasn't for Rome. Armenia with the help of Pontus and Parthia will be able to take Syria. However soon we could see Pontus and Armenia face off against Parthia as the three inevitably battle for Iraq.
Carthage is also being somewhat overestimated. While Carthage will be able to retain naval dominance over the western med. a probable conquest of Sicily, and rule of southern spain, it is unlikely they extend their control over the entirety of Iberia. For one thing Carhage plus all the Punic cities lacked the effective manpower to conquer these areas, especially when Carthage had enough problems with Corisca. Also how exactly will they deal with the Numidians, who will only get stronger and bigger while there is no more Phoenician settlers to bolster the Carthaginian numbers. However I will concede that Carthage will keep a monopoly on sea trade in the western Mediterranean, gaining clients every where it can.
One thing we should consider though, is that Rome still rules all of mainland Italy giving it huge manpower and tax base. Enough to mount a war against Carhage once again. In order to ensure Punic culture and the Carthaginian hegemony, is to remove Rome because unlike tthe others states of the Mediterranean, they did not quit and fought with the vision of an empire whereas Carthage and other city states fought only to ensure wealth and security and would attempt to peace out at the first sign of danger. It is likely that Rome still rises in the west but is unable to conquer the east. Idk enough about the Gauls to make any suggestions on their future, other than to get curbstomped by Rome.
Also a question, does anyone have any thoughts on a continued Maccabee state in this scenario?