So it seems better for you if the SDF controlled 1/3th of Syria if the US invades Iran?
Who is "you", Turkiye?
Firstly the US does not ask Turkiye to invade or bomb Iran, that is already their long term strategy and groups / proxy like YPG / PKK / SDG (names change but it is the same entity) together with the Iraqi Kurd groups (KDP, PUK) will IMO form the US proxy for Iran.
Do you guys really think that US and Israel would stay this silent if this "Syrian collapse" of SDG was not a planned one? There were a few "clashes" for the show but we saw a coordinated retreat / gathering of the US proxy preparing for the new task -> Iran