Package Control is currently a pure community project which is not related with SublimeHQ beyound them providing an easy to use installer plugin and sponsoring the hosting.
Will Bond is the inventor and original author. He worked at SublimeHQ for several years and is the only one with full access to all PC related repos/resources/servers, AFAIK.
I am just a volunteer - a power user as of 2016 - with push access to Package Control repo (the client part, which is installed on ST) as was contributing some significant changes which helped to start 4.0 branch.
I’ve also prepared a PR to update the webapp to 4.0 with support for python 3.8 at https://github.com/wbond/packagecontrol.io/pull/157.
Will is the only one who would be able to deploy that PR or sign and publish Package Control in a way which makes it accessible for ST’s installer plugin.
I’ve run the webapp in dev mode locally, but not on real production data. I am not familiar with the server infrastructure and - tbh - don’t feel confident enough to overtake its maintanance. I understand the basics of the webapp’s infrastructure, but I never got in touch with CoffeeScript which is used for frontend stuff.