Agree and concerning about earlier actions taken against political parties.
I do think our media got ahead of themselves (like they often do) on the recent announcements. From Meduza:
Top Ukrainian officials not fired — yet: Ukraine’s Prosecutor General Iryna Venediktova and SBU Chief Ivan Bakanov haven’t been fired yet, the Kyiv Independent reported on Monday, citing President Volodymyr Zelensky’s Deputy Chief of Staff Andriy Smyrnov. According to Smyrnov, the two top officials have been suspended for the duration of investigations into law enforcement officials suspected of collaborating with Russian forces. Whether Zelensky decides to file motions with the Ukrainian Parliament to dismiss Venediktova and Bakanov will depend on the outcome of the investigations, Smyrnov said.
I don't think the investigation is if they collaborated but rather if they did enough to investigate collaboration inside their organizations. Regardless, it looks like their is a process and it includes the parliament.
Additionally, Bakanov is a childhood friend of Zelensky, so he is going after his own people too.