To capture the burdensome detail of this scenario, can you unpack your probability estimates for each step - conditional on the previous - and any reasoning?
Using made-up numbers for an example:
This is just way way way too many conjunctions. I get , a little less than one percent, without the structural reform clause or new variant - but I'd love to see your numbers.
An alternative story:
The report will be ~500 pages long, and shrouded in an impenetrable dialect of bureaucratese. No-one in the world will read it in its entirety. A lot of people will cherry-pick bits that sound like they support their previous conclusion. Some people will declare that it proves the coronavirus was a deliberate Chinese bioweapon released to attack America and we should retaliate by nuking them. Some people will declare that it proves that discussion of the lab leak hypothesis has always been unfounded anti-Asian discriminatory hate speech. No-one will change their mind about anything or do anything different.
In the few cases where the report presents clear statements of fact, it will be pretended that they were already the viewpoint of experts. Any media outlets that made earlier statements incompatible with the report will quietly edit or simply ignore their past statements. Only a handful of people will notice or care about this.