The choco repository has recently changed the validation process that happens before a package is accepted and published. This means that osquery 4.5.1 is no longer considered as a valid package and is currently blocked.
We have Nick looking into it, and we'll know more about the actual issue once he has some more time to debug it 🙂
In the meantime, we have the packages uploaded on the osquery.io
website if they can be useful!