The most likely area of operations for new KSA support of the Syrian civil war would be within Northeastern districts of the country. The de facto administration of that section of Syria is the Kurdish-oriented govt known as the “Democratic Federation of Northern Syria”. This move by Saudi Arabia has some potential due to the US-backed SDF (Syrian democratic forces, also the official defense force of the Kurdish-centered govt in Syria) being outfitted as pro-western secular opposition to the Syrian govt. The formerly western-backed FSA (Free Syrian army) lost support from the US and the rest of the west due to their growing illegitimacy, this was caused by Islamist radicalisation within their ranks. The SDF doesn’t have as much negative baggage attached to their history, this means the international community would gain what’s recognized as a credible fighting force within Syria to oppose Assad. In-turn the Kurdish govt views Saudi Arabia in a positive light. For example it was Ilham Ehmed who is the Co-Chairman of the Syrian Democratic Council (the political wing of the US-backed Syrian Democratic Forces) stated back in October of 2017 that “Saudi Arabia is an important country it must play its role in promoting stability in Syria and we are ready to cooperate with it.”
Recently there’s been a disparity of interests between the YPG branch of the SDF and the US Coalition. The US may sever their support of the YPG to appease Turkey and sacrifice a greater fraction of Syria’s future territorial integrity. They may be expecting Turkey to conflict with the interests of the US-Coalition so long as YPG support remains. The Turks have been using the pretext of YPG affiliation with the PKK (The Kurdistan Workers Party, a terrorist organisation as designated by NATO ) in order to intervene within Syria. The recent creation of the Raqqa military council by the SNA (Turkish-backed Syrian National army of the FSA) with the aim to expel the YPG from the Raqqa governate is evidence of this.
Saudi Arabia will predictably support an Arab majority branch of the SDF designated as the Deir ez-Zor Military Council. The grim reality is that they are known to have questionable Islamist ideologies and to have been recruited from members of former FSA, al-qaeda and ISIS units. The most notable example would be their very own commanding officer, General Commander Rashid Abu Khawla who has a colourful past of running a criminal outfit that ran extortion checkpoints throughout Deir Ezzore in the earlier stages of the war before they pledged their allegiance to ISIS. Although ISIS initially allowed them to maintain their checkpoints Abu kwala and his men eventually fled Deir Ezzore for Al-Hasakah, startled by the excecution of Kwala’s brother Ata Allah on the charges of rape and bribery. Kwala would later move to Tel Abyad in Turkey before reappearing in Syria as the commander of the newly formed Deir Ezzor Military Council.
It remains to be seen whether or not Saudi Arabia will neglect to support the YPG. This would present Saudi Arabian de facto consent to present-day Turkey’s judiciary methods of militarily imposed disciplinary actions towards PKK affiliated organizations.