Any incursion into Turkey held areas in the north Turkey will go Berserk and people will demand blood, it is not the right time to be asking for war with Turkey.
I don’t know why they are pulling troops there, it could be to stop a possible push from rebels, it makes no sense.
They don't need to advance on The North Part. But they can pressure by Shelling per exemple or Harass IF TR still try to keep Idlib after the start of Idlib op.
The Regime, think it's the End of the Conflict, That this last pocket is the last obstacle to the "Win", So you just need a rogue unit or the likes of Regime soldiers During Afrin op per exemple, to just feed the fire.
It's a "Show of Power" and a "Psychological war" toward TR BUT mostly toward FSA in the North and Idlib. It's not only about TR.
One of the Condition for ASSad/RU/IR to have a "peaceful" campaign in Idlib and beyond is to trigger "doubt" among rebel factions. A simple exemple is "Look rebels, I am doing it and Now what? Are you sure TR will help you if I advance" and Therefore Wish to push for "Infighting" that will result in TR losing Indirectly Idlib.
And You can see that few factions in Idlib, Also surfing of ASSAd/RU/IR strategy, like HTS per exemple, Where they feed the "TR will sell out Idlib or TR will make a deal with RU and give Idlib to keep the North part" etc...
TR success to keep Idlib lay on it's ability to maintain a common front and impose some sort of "Discipline" among factions. And for that, She has to make others see her as "Strong" Toward RU/IR/ASSad.
Per exemple, Her part in the last Summit was also a "Show of Force" Or The sending of Reinforcement . All of that is a way to keep Idlib and North front in check against the regime strategy... on "Divide and Conquer"
The Moment the Regime "Believe" that TR will not "Help" in Idlib, She will start the op. That's one of their Green light. So any perceived Weakness they may "see", they will move on it.
Both Sides are reading to fight... It's only a matter of "Support".