Good analysis.
General Zaheer thought that like the 90s, Nawaz will pick a fight with army. He will think Raheel is behind the dharna (there is a recording of a call where Zaheer is telling generals what Raheel had told him, but it never happened). So when Nawaz fires Raheel, the army will takeover and topple Nawaz.
But why Fire Raheel?
Kayani wanted pasha to serve extra term as ISI chief. But Gilani refused. So Kayani picked Zaheer. The top few generals were given as a list for next COAS. Raheel was from a department that usually doesn't produce COAS and Kayani didn't wish him to become one. Thus Nawaz picked Raheel, to go against Raheel. Also he didn't make the top 2 other generals COAS, who were also a pick of Kayani and neither did he make Zaheer.
Then when Hamid Mir was attacked and govt sided with Geo, it pissed Zaheer off and then the whole dharna talk started where Imran was led to believe that military will topple Nawaz and he was told he needed dead bodies. Failure of Imran, he was then told to attack parliament, again not producing dead bodies.
Raheel had said the army will protect state institutions, so when PTV was attacked and there were army insiders found in there, Raheel found out that someone was helping PTI out.
Then Nawaz had produced an audio tape to Raheel , courtesy of IB which works for govt and has tried in past to prevent coup as well, where Zaheer is found telling other generals something Raheel told him. Raheel calls Zaheer and plays tape. Asks him did I say it, and Zaheer says no. Then he asks him to leave. Raheel finds out that the intention of dharna was not to have Nawaz toppled, but Raheel fired, so army could intervene.
Back in 98, Nawaz fired a COAS. He was apolitical so he did not allow army to topple Nawaz. So Zaheer thought he will make same mistake he made 3 times in 90s, Fire the COAS. Since Raheel was apolitical, he needed to be gotten rid off, because like jehangir karamat, he did not allow coup, but Musharraf did. So using Raheel as an excuse, Zaheer and some corps commander/generals would topple Nawaz regime, call new election and maybe give PTI interim govt.
Now you may ask: Why doesn't Nawaz open commission then?
Answer: Zaheer wanted Nawaz to pick a fight with army. Nawaz learned from his mistake in the 90s, hence he did not even Fire Zaheer after audio tape back in August/September. Now that the battle is won, why fight the army? There are still followers of Zaheer, Kayani and Pasha left who may topple govt one day. Besides, even if commission is formed, will these generals go to jail? Look at Musharraf, he's untouchable, despite being out of army for over 8 years. Generals that retired so recently are bound to have even more sympathizers/followers.