so these are Turkish trained, supplied and supported forces fighting against the de facto legal and legitimate government of Syria?
Briefly, YES; elaborately, NO
The opposition generally opposes the government because it is heavily dominated by Shia Alawites, representing a population of about 8%, governing over the 80% Sunni majority population. This imbalance has been one of the main reasons for the civil war. As a result, groups like Al-Nusra and other Sunni factions have emerged in significant numbers.
In the early stages of the war, the opposition was widely supported by various countries, similar to Ukraine, including the US, Europe, and Saudi Arabia. However, over time, the focus shifted under the banner of the SDF, uniting predominantly Kurdish groups like the YPG. Currently, the FSA, now rebranded as the SNA, only receives support from Turkey and Qatar. By 2020, just before the COVID-19 pandemic, the opposition was essentially defeated. They can only survive in areas controlled by Turkey, which is why everything they rely on, from the backpacks on their shoulders to their underwear, comes from Turkey.
The issue now lies with Aleppo, which is considered the Sunni capital of Syria. This has resulted in millions of Sunni Arab refugees in Turkey. At present, Aleppo is controlled by Nusayri (Arabic Shia) forces, a handful of Russian, Iranian milita and Hezbollah fighters—it is not even their native region. This is why they struggle to maintain control over the area. Without Russian air defense systems and Iranian generals like Soleimani, the Nusayri Syrian conscripts would not be able to hold Aleppo.
I've been sharing this on forum for months: Turkey's support for Palestine is a paper tiger. The main goal is to push back Iranian and communist Kurdish militants, as well as demolishing Russian bases, from the border. Before Trump came to power, Turkey must clear the remaining YPG enclaves in places like Manbij and Tel Rifaat. By opening a new front to keep the Syrian government busy with Rebels & Nusra will allow Turkey to fully complete the tasks it left unfinished in 2019. If the northern Syrian opposition gains control and a ceasefire is established, the 8 million Sunni refugees in Turkey could finally return to their homes.