Unable to install via WoWUp: "A valid zip file is required to be in the release (directory, presumably) in order for WowUp to download it". Can this be added to the github page?

See https://github.com/BigWigsMods/packager for details (hah!).

To clarify, the message now reads: "A valid zip file ending with '-bc' is required in order for WowUp to download it."

This applies for TBC-classic obviously :)

well now that cursedforge has closed the api, and therefore wowup removed it (and added some direct github support) i think is time to make it available

See #309 (comment) I made something available.