I don't think '
they did their research in advance', even though it was already known (or at least published) that Zinc was effective against the original SARS.
I think they thought they had something that could not be easily thwarted.
From the original abstract of the letter entitled
A SARS-like cluster of circulating bat coronaviruses shows potential for human emergence in
Nature dated 09 November 2015
https://www.nature.com/articles/nm.3985:
From the (original) Abstract:
Using the SARS-CoV reverse genetics system2, we generated and characterized a chimeric virus expressing the spike of bat coronavirus SHC014 in a mouse-adapted SARS-CoV backbone. The results indicate that group 2b viruses encoding the SHC014 spike in a wild-type backbone can efficiently use multiple orthologs of the SARS receptor human angiotensin converting enzyme II (ACE2), replicate efficiently in primary human airway cells and achieve in vitro titers equivalent to epidemic strains of SARS-CoV. Additionally, in vivo experiments demonstrate replication of the chimeric virus in mouse lung with notable pathogenesis. Evaluation of available SARS-based immune-therapeutic and prophylactic modalities revealed poor efficacy; both monoclonal antibody and vaccine approaches failed to neutralize and protect from infection with CoVs using the novel spike protein. On the basis of these findings, we synthetically re-derived an infectious full-length SHC014 recombinant virus and demonstrate robust viral replication both in vitro and in vivo. Our work suggests a potential risk of SARS-CoV re-emergence from viruses currently circulating in bat populations.
(all emphases mine)
Now, the Abstract was edited later, and there was a disclaimer posted above the article which said that this article should not be used to infer that SARS-CoV-2 had a lab origin, but the description of a Chimera Virus with the above characteristics fits like a well tailored glove with SARS-CoV-2.
However, I do not believe that those who generated and later released the virus realized that there are several Ionophores, among them Ivermectin and Hydroxychloroquine, which would get the Zinc ions into the cytoplasm to interfere with viral replication, and when those were discovered and made public, the 'War on Drugs' took on a new aspect as the Medical Establishment sought to discredit the treatments with a full-on propaganda campaign in the Mass Media, censorship in the electronic media (from You Tube pulling Dr Zelenko's video to Twitter and Facebook and elsewhere censoring or branding unofficial information as "misinformation" and steering people toward the official narrative.
The combination of making the drugs harder to obtain affected even those taking them for other reasons, and coupled with the propaganda campaign, served to keep many from considering a cheap, effective, early onset treatment.
Only God knows how many died or died prematurely as a result of that, but the numbers are likely in the millions, not even counting the economic and social devastation wrought on the World as others followed the CDC/WHO lead.