We have received a few inquiries on why the Windows desktop app has not yet been updated to v1.3.0 on our downloads page https://about.mattermost.com/downloads/
The Windows 1.3 release has been delayed by code-signing, which was originally scheduled for 16th, then it was 18th, but we're still waiting.
The delay is administrative and we're simply waiting for validation from Microsoft. The delay was unforeseen, and we'll upgrade the version as soon as the validation has been completed.
Sorry for the wait, we're eager to release the new version soon!