I have no firm idea as to where the Sochi talks will go however the following underlying interests maybe relevant.
Firstly, the attempted Turkish invasion of the North did not go well for Turkey. Even with the military advantage of pin point air strikes, pin point heavy artillery and high tech drones the Islamo-fascist militias suffered similar casualty rates to the SDF. This is because the SDF front line troops are extremely well trained in multiple combat scenarios while Erdogan's militias are not. None-the-less, Turkey will undoubtedly hold onto the northern border areas occupied during the latest incursion.
Secondly. SDF performance against overwhelming odds would not go unnoticed. After 9 years of turmoil and war the Assad army is reportedly depleted to around 20,000 combat ready troops. The rest maybe better described as Dad's Army reservists. If Assad were logical, the Russian suggestion of amalgamating the SAA and aligned elements of the SDF would be extremely tempting as it would at least double the combat ready troops at hand. That would tip the balance, The military and political leverage of Al Qaeda and Islamo-fascist militias (and Turkey) would be greatly reduced by such a move.
Thirdly Only a small percentage of the population is Alawite or Shia. While noting that Sunni Muslims have been fighting on all sides of this conflict it would be fortuitous for the future Syrian Government to embed a Sunni block in its ranks which is where the Kurds and like minded & aligned Arab tribes could fit in.
Challenges
There is an endless list of challenges starting with the historic inflexibility and fiefdom mentality of the Assad regime. To move forward they need to give in a little more than they are used to or want to. Similarly while the north can and should be self administrating (on non-military matters) it won't be structured on the Bookchin model that was implemented by the Autonomous Administration.
Observations
The arrival of more Russian Military Police in Qamishlo flags an intention to patrol the border, from Iraq to Mashrafat in conjunction with the Syrian Army. Erdogan is less likely to attempt rolling over the top of the SAA with the Russians also present. For now, I see the Kurdish elements of the YPG withdrawing from the border. My expectation is that the SAA will with a Russian Presence also control the border zone from Korbani to the current lines of control.
Reconciliation
Any pathway to reconciliation will long, arduous and difficult to manage however it is the only alternative to balkanisation of the country into two or maybe three mini-states (including and al Qaeda Mini State). Is there a Mandella in the house somewhere? Assad isn't the man and some of those from the north who could have done the job effectively have been executed (by Turkey). A face saving (for all sides) compromise on Assad's role can be worked out IMHO.
The US
It's not possible to backflip policy on a daily or weekly basis and achieve any form of long term outcome. Policy in the run doesn't work. What's done is done and can't be simply reversed because the people of the north have lost faith in US assurances.
Today's news is that Trump says he gave no assurances which is sort of true because Pompeo gave the Kurds assurances for and on behalf of Trump.
Now Trump wants to hold most of Syria's oil fields with a grand total of 200 troops. The US may do better focussing on a political solution that ensures that Syria is strong enough to act as something other than Iran's proxy.
