I must have missed something in the parler story.
The "hack" story from lb reads more like liberal script kiddie fanfiction than anything else. While the attack vector described is potentially plausible, the attack scope and scale seems rather exaggerated. Propagating new accounts "by the millions" across a server network and then using them for downloading all of the data using a botnet would radically exceed the infrastructure capabilities of parler unless performed over weeks, and surely someone would notice the admin account growth.
This would also assume the admin accounts were created in the same way user accounts were and the process was the same.
Again, you might be able to use it on a small scale, but the large operation indicated by the post would immediately trigger alerts at any NOC. I've been among people who are remote administrators and watched even small scale web operations up close. What is described in that post would simply not succeed to the degree implied.